serial: kgdb_nmi: remove redundant initialization of variable c

The variable c is being initialized with a value that is never
read, it is being updated later on. The assignment is redundant and
can be removed.

Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Addresses-Coverity: ("Unused value")
Link: https://lore.kernel.org/r/20210513230224.138859-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

serial: sh-sci: Add support for RZ/G2L SoC

Add serial support for RZ/G2L SoC with earlycon and
extended mode register support.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20210514192218.13022-11-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

dt-bindings: serial: renesas,scif: Document r9a07g044 bindings

Document R9A07G044 SoC variants, common compatiable string
"renesas,scif-r9a07g044" is added for RZ/G2L and RZ/G2LC SoC.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210514192218.13022-10-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: serial: meson: retrieve port FIFO size from DT

Now the DT bindings has a property to get the FIFO size for a particular port,
retrieve it and use to setup the FIFO interrupts threshold.

Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lore.kernel.org/r/20210518075833.3736038-3-narmstrong@baylibre.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

dt-bindings: serial: amlogic, meson-uart: add fifo-size property

On most of the Amlogic SoCs, the first UART controller in the "Everything-Else"
power domain has 128bytes of RX & TX FIFO, so add an optional property to describe
a different FIFO size from the other ports (64bytes).

Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lore.kernel.org/r/20210518075833.3736038-2-narmstrong@baylibre.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: hvc_iucv: Drop unnecessary NULL check after container_of

The result of container_of() operations is never NULL unless the extracted
element is the first element of the embedded structure. This is not the
case here. The NULL check is therefore unnecessary and misleading.
Remove it.

This change was made automatically with the following Coccinelle script.

@@
type t;
identifier v;
statement s;
@@

<+...
(
  t v = container_of(...);
|
  v = container_of(...);
)
  ...
  when != v
- if (\( !v \| v == NULL \) ) s
...+>

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20210511012519.2359074-1-linux@roeck-us.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

vt: Move custom isspace() to its own namespace

If by some reason any of the headers will include ctype.h
we will have a name collision. Avoid this by moving isspace()
to the dedicate namespace.

First appearance of the code is in the commit 24a1c2a769cf
("Import 1.1.92").

Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210510144947.58270-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: tty_port: Fix coding style issues of block comments

Fix coding style issues of block comments, reported by checkpatch.pl.
Besides, add a period at the end of the sentenses.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1620811585-18582-18-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: tty_port: Add a blank line after declarations

Add a blank line after declarations, reported by checkpatch.pl.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1620811585-18582-17-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: tty_port: Delete a blank line before EXPORT_SYMBOL(foo)

Delete a blank line before EXPORT_SYMBOL(foo) so that
EXPORT_SYMBOL(foo) immediately follow its function/variable,
reported by checkpatch.pl.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1620811585-18582-16-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: tty_io: Remove return in void function

Remove return in void function, reported by checkpatch.pl.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1620811585-18582-15-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: tty_io: Delete a blank line before EXPORT_SYMBOL(foo)

Delete a blank line before EXPORT_SYMBOL(foo) so that EXPORT_SYMBOL(foo)
immediately follow its function/variable, reported by checkpatch.pl.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1620811585-18582-14-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: tty_io: Fix an issue of code indent for conditional statements

Fix an issue of code indent for conditional statements,reported by
checkpatch.pl.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1620811585-18582-13-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: tty_io: Remove the repeated word 'can'

Remove the repeated word 'can' following advice of checkpatch.pl

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1620811585-18582-12-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: tty_io: Fix coding style issues of block comments

Fix coding style issues of block comments, reported by checkpatch.pl.
Besides, add a period at the end of the sentenses.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1620811585-18582-11-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: tty_io: Fix trailing whitespace issues

Fix trailing whitespace issues, reported by checkpatch.pl.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1620811585-18582-10-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: tty_io: Fix spaces required around that ':'

Fix spaces required around that ':', reported by checkpatch.pl.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1620811585-18582-9-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: tty_io: Add a blank line after declarations

Add a blank line after declarations, reported by checkpatch.pl.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1620811585-18582-8-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: tty_io: Remove spaces before tabs

Remove spaces before tabs following the advice of checkpatch.pl.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1620811585-18582-7-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: tty_buffer: Fix coding style issues of block comments

Fix coding style issues of block comments, reported by checkpatch.pl.
Besides, add a period at the end of the sentenses.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1620811585-18582-6-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: tty_buffer: Remove the repeated word 'the'

Remove the repeated word 'the' following advice of checkpatch.pl
Besides, add a period at the end of comment sentence.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1620811585-18582-5-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: tty_buffer: Add a blank line after declarations

Add a blank line after declarations, reported by checkpatch.pl.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1620811585-18582-4-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: tty_baudrate: Fix coding style issues of block comments

Fix coding style issues of block comments, reported by checkpatch.pl.
Besides, add a period at the end of comment sentenses.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1620811585-18582-3-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: tty_baudrate: Remove unnecessary tab and spaces in comment sentence

Remove unnecessary tab and spaces in comment sentence, reported
by checkpatch.pl.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Link: https://lore.kernel.org/r/1620811585-18582-2-git-send-email-tanxiaofei@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: nozomi: Fix a resource leak in an error handling function

A 'request_irq()' call is not balanced by a corresponding 'free_irq()' in
the error handling path, as already done in the remove function.

Add it.

Fixes: 9842c38e9176 ("kfifo: fix warn_unused_result")
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/4f0d2b3038e82f081d370ccb0cade3ad88463fe7.1620580838.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ttyprintk: Removed unnecessary TTY ioctl callback

It turns-out, that TIOCCONS is completely handled in tty_io.c, so
the current local ioctl callback is of no real use.

Signed-off-by: Samo Pogačnik <samo_pogacnik@t-2.net>
Link: https://lore.kernel.org/r/1502946c760b1aae3ad9cffcf4ea3b9f37206585.camel@t-2.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ttyprintk: Add TTY port shutdown callback

By adding the TTY port shutdown callback, the final buffer flush has
been moved from tpk_close() to tpk_port_shutdown(). This enables buffer
flush upon close and hangup as well. The change also removes the
specific 'buf == NULL' handling in tpk_printk(), which became useless.

Signed-off-by: Samo Pogačnik <samo_pogacnik@t-2.net>
Link: https://lore.kernel.org/r/f236ea26520fbef176fefec2e06a43548f63fa9c.camel@t-2.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: serial: sb1250-duart: include <linux/io.h> instead of <asm/io.h>

Include the more general linux/io.h instead of asm/io.h
as checkpatch suggests.

Signed-off-by: Zihao Tang <tangzihao1@hisilicon.com>
Signed-off-by: Jay Fang <f.fangjian@huawei.com>
Link: https://lore.kernel.org/r/1620874904-39285-13-git-send-email-f.fangjian@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: serial: vr41xx_siu: include <linux/io.h> instead of <asm/io.h>

Include the more general linux/io.h instead of asm/io.h
as checkpatch suggests.

Signed-off-by: Zihao Tang <tangzihao1@hisilicon.com>
Signed-off-by: Jay Fang <f.fangjian@huawei.com>
Link: https://lore.kernel.org/r/1620874904-39285-12-git-send-email-f.fangjian@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: serial: sunzilog: include <linux/io.h> instead of <asm/io.h>

Include the more general linux/io.h instead of asm/io.h
as checkpatch suggests.

Signed-off-by: Zihao Tang <tangzihao1@hisilicon.com>
Signed-off-by: Jay Fang <f.fangjian@huawei.com>
Link: https://lore.kernel.org/r/1620874904-39285-11-git-send-email-f.fangjian@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: serial: sunsu: include <linux/io.h> instead of <asm/io.h>

Include the more general linux/io.h instead of asm/io.h
as checkpatch suggests.

Signed-off-by: Zihao Tang <tangzihao1@hisilicon.com>
Signed-off-by: Jay Fang <f.fangjian@huawei.com>
Link: https://lore.kernel.org/r/1620874904-39285-10-git-send-email-f.fangjian@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: serial: sunsab: include <linux/io.h> instead of <asm/io.h>

Include the more general linux/io.h instead of asm/io.h
as checkpatch suggests.

Signed-off-by: Zihao Tang <tangzihao1@hisilicon.com>
Signed-off-by: Jay Fang <f.fangjian@huawei.com>
Link: https://lore.kernel.org/r/1620874904-39285-9-git-send-email-f.fangjian@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: serial: txx9: include <linux/io.h> instead of <asm/io.h>

Include the more general linux/io.h instead of asm/io.h
as checkpatch suggests.

Signed-off-by: Zihao Tang <tangzihao1@hisilicon.com>
Signed-off-by: Jay Fang <f.fangjian@huawei.com>
Link: https://lore.kernel.org/r/1620874904-39285-8-git-send-email-f.fangjian@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: serial: pmac_zilog: include <linux/io.h> insteiad of <asm/io.h>

Include the more general linux/io.h instead of asm/io.h
as checkpatch suggests.

Signed-off-by: Zihao Tang <tangzihao1@hisilicon.com>
Signed-off-by: Jay Fang <f.fangjian@huawei.com>
Link: https://lore.kernel.org/r/1620874904-39285-7-git-send-email-f.fangjian@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: serial: mux: include <linux/io.h> instead of <asm/io.h>

Include the more general linux/io.h instead of asm/io.h
as checkpatch suggests.

Signed-off-by: Zihao Tang <tangzihao1@hisilicon.com>
Signed-off-by: Jay Fang <f.fangjian@huawei.com>
Link: https://lore.kernel.org/r/1620874904-39285-6-git-send-email-f.fangjian@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: serial: ip22zilog: include <linux/io.h> instead of <asm/io.h>

Include the more general linux/io.h instead of asm/io.h
as checkpatch suggests.

Signed-off-by: Zihao Tang <tangzihao1@hisilicon.com>
Signed-off-by: Jay Fang <f.fangjian@huawei.com>
Link: https://lore.kernel.org/r/1620874904-39285-5-git-send-email-f.fangjian@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: serial: icom: include <linux/io.h> instead of <asm/io.h>

Include the more general linux/io.h instead of asm/io.h
as checkpatch suggests.

Signed-off-by: Zihao Tang <tangzihao1@hisilicon.com>
Signed-off-by: Jay Fang <f.fangjian@huawei.com>
Link: https://lore.kernel.org/r/1620874904-39285-4-git-send-email-f.fangjian@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: serial: dz: include <linux/io.h> instead of <asm/io.h>

Include the more general linux/io.h instead of asm/io.h
as checkpatch suggests.

Signed-off-by: Zihao Tang <tangzihao1@hisilicon.com>
Signed-off-by: Jay Fang <f.fangjian@huawei.com>
Link: https://lore.kernel.org/r/1620874904-39285-3-git-send-email-f.fangjian@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: serial: atmel: include <linux/io.h> instead of <asm/io.h>

Include the more general linux/io.h instead of asm/io.h
as checkpatch suggests.

Signed-off-by: Zihao Tang <tangzihao1@hisilicon.com>
Signed-off-by: Jay Fang <f.fangjian@huawei.com>
Link: https://lore.kernel.org/r/1620874904-39285-2-git-send-email-f.fangjian@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: remove unused tty_throttle

The last user was removed in commit e91e52e42814 (n_tty: Fix stuck
throttled driver) in 2013. So remove exported tty_throttle completely.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210510065923.5112-1-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

isdn: capi, drop useless pr_debugs

capi have many pr_debugs in tty_operations hooks to print only a
functions name. We have better debugging aids in the kernel many years
now. So remove these useless pr_debugs.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: netdev@vger.kernel.org
Link: https://lore.kernel.org/r/20210505091928.22010-34-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

isdn: capi, remove optional tty ops

break_ctl and set_ldisc are optional tty_operations hooks. Given capi
does nothing useful in them, just remove these.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: netdev@vger.kernel.org
Link: https://lore.kernel.org/r/20210505091928.22010-33-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: remove empty tty_operations::set_termios

tty_operations::set_termios is optional. If it doesn't exist, nothing is
called. So remove almost¹ empty set_termios implementations.

¹ capi had an useless pr_debug in it.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Karsten Keil <isdn@linux-pingi.de>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Link: https://lore.kernel.org/r/20210505091928.22010-32-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: remove empty tty_operations::flush_buffer

tty_operations::flush_buffer is optional. If it doesn't exist, nothing
is called. So remove almost¹ empty flush_buffer implementations.

¹ capi had an useless pr_debug in it.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Link: https://lore.kernel.org/r/20210505091928.22010-31-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

nozomi: simplify ntty_chars_in_buffer

ntty_chars_in_buffer is overly complicated. Simplify it by inverting the
condition.

Side FIXME: how can dc or port be NULL here?

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210505091928.22010-29-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: make tty_operations::chars_in_buffer return uint

tty_operations::chars_in_buffer is another hook which is expected to
return values >= 0. So make it explicit by the return type too -- use
unsigned int.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Acked-by: David Sterba <dsterba@suse.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Cc: Jens Taprogge <jens.taprogge@taprogge.org>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Lin <dtwlin@gmail.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Alex Elder <elder@kernel.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Mathias Nyman <mathias.nyman@intel.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Link: https://lore.kernel.org/r/20210505091928.22010-27-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: remove tty_operations::chars_in_buffer for non-buffering

The only user of tty_ops::chars_in_buffer is tty_chars_in_buffer. And it
considers tty_ops::chars_in_buffer optional. In case it's NULL, zero is
returned. So remove all those chars_in_buffer from tty_ops which return
zero. (Zero means such driver doesn't buffer.)

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Richard Henderson <rth@twiddle.net>
Acked-by: Max Filippov <jcmvbkbc@gmail.com> # xtensa
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Chris Zankel <chris@zankel.net>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Link: https://lore.kernel.org/r/20210505091928.22010-26-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: make tty_buffer_space_avail return uint

tty_buffer_space_avail returns values >= 0, so make it clear by the
return type.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20210505091928.22010-25-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: make tty_operations::write_room return uint

Line disciplines expect a positive value or zero returned from
tty->ops->write_room (invoked by tty_write_room). So make this
assumption explicit by using unsigned int as a return value. Both of
tty->ops->write_room and tty_write_room.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Acked-by: Alex Elder <elder@linaro.org>
Acked-by: Max Filippov <jcmvbkbc@gmail.com> # xtensa
Acked-by: David Sterba <dsterba@suse.com>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Chris Zankel <chris@zankel.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Cc: Jens Taprogge <jens.taprogge@taprogge.org>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Scott Branden <scott.branden@broadcom.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Lin <dtwlin@gmail.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Mathias Nyman <mathias.nyman@intel.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Link: https://lore.kernel.org/r/20210505091928.22010-23-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ti-st: use tty_write_room

Don't access tty->ops->write_room directly, use tty_write_room helper
instead.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20210505091928.22010-22-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ti-st: use goto-failpath in st_core_init

Use the classic failpath handling using gotos in st_core_init. That way,
tty_unregister_ldisc needs not be repeated on two places.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20210505091928.22010-21-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: return void from tty_unregister_ldisc

Now that noone checks the return value of tty_unregister_ldisc, make the
function return 'void'.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210505091928.22010-20-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: no checking of tty_unregister_ldisc

tty_unregister_ldisc now returns 0 = success. No need to check the
return value. In fact, the users only warned if an error occured and
didn't do anything useful anyway -- the ldisc module was unloaded in any
case.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: William Hubbs <w.d.hubbs@gmail.com>
Cc: Chris Brannon <chris@the-brannons.com>
Cc: Kirk Reiser <kirk@reisers.ca>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rodolfo Giometti <giometti@enneenne.com>
Cc: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Link: https://lore.kernel.org/r/20210505091928.22010-19-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: drop tty_ldisc_ops::refcount

The refcount is checked only in tty_unregister_ldisc and EBUSY returned
if it is nonzero. But none of the tty_unregister_ldisc callers act
anyhow if this (or any other) error is returned. So remove
tty_ldisc_ops::refcount completely and make tty_unregister_ldisc return
'void' in the next patches. That means we assume tty_unregister_ldisc is
not called while the ldisc might be in use. That relies on
try_module_get in get_ldops and module_put in put_ldops.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210505091928.22010-18-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: make tty_ldisc_ops a param in tty_unregister_ldisc

Make tty_unregister_ldisc symmetric to tty_register_ldisc by accepting
struct tty_ldisc_ops as a parameter instead of ldisc number. This avoids
checking of the ldisc number bounds in tty_unregister_ldisc.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: William Hubbs <w.d.hubbs@gmail.com>
Cc: Chris Brannon <chris@the-brannons.com>
Cc: Kirk Reiser <kirk@reisers.ca>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rodolfo Giometti <giometti@enneenne.com>
Cc: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Link: https://lore.kernel.org/r/20210505091928.22010-17-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

n_gsm: use goto-failpaths in gsm_init

Use the classic failpath handling using gotos in gsm_init. That way,
tty_unregister_ldisc needs not be repeated on two places.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210505091928.22010-16-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: set tty_ldisc_ops::num statically

There is no reason to pass the ldisc number to tty_register_ldisc
separately. Just set it in the already defined tty_ldisc_ops in all the
ldiscs.

This simplifies tty_register_ldisc a bit too (no need to set the num
member there).

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: William Hubbs <w.d.hubbs@gmail.com>
Cc: Chris Brannon <chris@the-brannons.com>
Cc: Kirk Reiser <kirk@reisers.ca>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Rodolfo Giometti <giometti@enneenne.com>
Cc: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Link: https://lore.kernel.org/r/20210505091928.22010-15-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: cumulate and document tty_struct::ctrl* members

Group the ctrl members under a single struct called ctrl. The new struct
contains 'pgrp', 'session', 'pktstatus', and 'packet'. 'pktstatus' and
'packet' used to be bits in a bitfield. The struct also contains the
lock protecting them to share the same cache line.

Note that commit c545b66c6922b (tty: Serialize tcflow() with other tty
flow control changes) added a padding to the original bitfield. It was
for the bitfield to occupy a whole 64b word to avoid interferring stores
on Alpha (cannot we evaporate this arch with weird implications to C
code yet?). But it doesn't work as expected as the padding
(tty_struct::ctrl_unused) is aligned to a 8B boundary too and occupies
some bytes from the next word.

So make it reliable by:
1) setting __aligned of the struct -- that aligns the start, and
2) making 'unsigned long unused[0]' as the last member of the struct --
   pads the end.

Add a kerneldoc comment for this grouped members.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Link: https://lore.kernel.org/r/20210505091928.22010-14-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: cumulate and document tty_struct::flow* members

Group the flow flags under a single struct called flow. The new struct
contains 'stopped' and 'tco_stopped' bools which used to be bits in a
bitfield. The struct also contains the lock protecting them to
potentially share the same cache line.

Note that commit c545b66c6922b (tty: Serialize tcflow() with other tty
flow control changes) added a padding to the original bitfield. It was
for the bitfield to occupy a whole 64b word to avoid interferring stores
on Alpha (cannot we evaporate this arch with weird implications to C
code yet?). But it doesn't work as expected as the padding
(tty_struct::unused) is aligned to a 8B boundary too and occupies some
bytes from the next word.

So make it reliable by:
1) setting __aligned of the struct -- that aligns the start, and
2) making 'unsigned long unused[0]' as the last member of the struct --
   pads the end.

This is also the perfect time to start the documentation of tty_struct
where all this lives. So we start by documenting what these bools
actually serve for. And why we do all the alignment dances. Only the few
up-to-date information from the Theodore's comment made it into this new
Kerneldoc comment.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: "Maciej W. Rozycki" <macro@orcam.me.uk>
Link: https://lore.kernel.org/r/20210505091928.22010-13-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: make fp of tty_ldisc_ops::receive_buf{,2} const

Char pointer (cp) passed to tty_ldisc_ops::receive_buf{,2} is const.
There is no reason for flag pointer (fp) not to be too. So switch it in
the definition and all uses.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: William Hubbs <w.d.hubbs@gmail.com>
Cc: Chris Brannon <chris@the-brannons.com>
Cc: Kirk Reiser <kirk@reisers.ca>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: Andreas Koensgen <ajk@comnets.uni-bremen.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Link: https://lore.kernel.org/r/20210505091928.22010-12-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

n_tty: remove superfluous return from n_tty_receive_signal_char

A return at the end of a void-returning function is superfluous. Get rid
of it.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210505091928.22010-11-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

n_tty: invert TTY_NORMAL condition in n_tty_receive_buf_standard

Handle !TTY_NORMAL as a short path and 'continue' the loop. Do the rest as
a normal code flow. This decreases the indentation level by one and
makes the code flow more understandable.

IOW, we avoid
  if (cond) {
    LONG CODE;
  } else
    single_line();
by
  if (!cond) {
    single_line();
    continue;
  }
  LONG CODE;

While at it, invert also the 'if (!test_bit) A else B' into 'if
(test_bit) B else A'.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210505091928.22010-10-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

n_tty: do only one cp dereference in n_tty_receive_buf_standard

It might be confusing for readers: there are three distinct dereferences
and increments of 'cp' in n_tty_receive_buf_standard. Do it on a single
place, along with/before the 'fp' dereference.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210505091928.22010-9-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

n_tty: make n_tty_receive_char_special return void

After the previous patch, noone cares about the return value of
n_tty_receive_char_special. ldata->lnext is checked instead.

So switch return type of n_tty_receive_char_special to void.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210505091928.22010-8-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

n_tty: move lnext handling

Move lnext handling from __receive_buf to n_tty_receive_buf_standard. It
simplifies the handling as it needs not fetching 'flag' and decrement
'count' in __receive_buf. Instead, all this is left up to the loop in
n_tty_receive_buf_standard which already does that.

This way, no need to repeat the action when n_tty_receive_char_special
returns true -- ldata->lnext is set there in that case, so the 'if
(ldata->lnext)' check is sufficient. The next patch will switch
n_tty_receive_char_special to return 'void'.

The result is much simplified code flow.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210505091928.22010-7-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

n_tty: drop parmrk_dbl from n_tty_receive_char

After the previous cleanup patches, parmrk_dbl parameter is always true
-- I_PARMRK is checked only in n_tty_receive_char now. So remove
parmrk_dbl completely.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210505091928.22010-6-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

n_tty: drop n_tty_receive_buf_fast

After the previous patches, n_tty_receive_buf_standard and
n_tty_receive_buf_fast differ only in handling of tty line and input
controls. Unlike n_tty_receive_buf_fast, n_tty_receive_buf_standard
handles them all (I_ISTRIP, I_IUCLC, L_IEXTEN, L_EXTPROC, and I_PARMRK).

So remove n_tty_receive_buf_fast and let n_tty_receive_buf_standard do
the handling. Actually most of the tests are only moved from
__receive_buf to n_tty_receive_buf_standard.

Again, the code duplication is not worth the theoretical speedup.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210505091928.22010-5-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

n_tty: remove n_tty_receive_char_fast

n_tty_receive_char_fast is a copy of n_tty_receive_char with one
exception: PARMRK is not doubled in the former. Unify these two and
double PARMRK depending on a newly added parameter (bool parmrk_dbl).

I don't think the theoretical speedup is worth the code duplication.
Which is directly connected with maintenance burden.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210505091928.22010-4-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

n_tty: remove n_tty_receive_char wrapper

The wrapper was meant as an optimization in commits eb3e4668bd9e (n_tty:
Un-inline slow-path n_tty_receive_char()) and e60d27c4d8b3 (n_tty:
Factor LNEXT processing from per-char i/o path). But the current
compiler (gcc 10) inlines it anyway (as expected). Actually, I'm not
sure it ever didn't. It would need to be marked with the noinline
attribute.

So remove this useless wrapper.

And if we ever introduce something similar, we need confirming numbers
first.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210505091928.22010-3-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: remove broken r3964 line discipline

Noone stepped up in the past two years since it was marked as BROKEN by
commit c7084edc3f6d (tty: mark Siemens R3964 line discipline as BROKEN).
Remove the line discipline for good.

Three remarks:
* we remove also the uapi header (as noone is able to use that interface
  anyway)
* we do *not* remove the N_R3964 constant definition from tty.h, so it
  remains reserved.
* in_interrupt() check is now removed from vt's con_put_char. Noone else
  calls tty_operations::put_char from interrupt context.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210505091928.22010-2-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

serial: 8250_omap: fix a timeout loop condition

This loop ends on -1 so the error message will never be printed.

Fixes: 4bcf59a5dea0 ("serial: 8250: 8250_omap: Account for data in flight during DMA teardown")
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/YIpd+kOpXKMpEXPf@mwanda
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

serial: 8250: Add an empty line and remove some useless {}

This fixes the following checkpatch.pl warnings:
   WARNING: Missing a blank line after declarations
   WARNING: braces {} are not necessary for any arm of this statement

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/257ffd691b4a062ad017333c9430d69da6dbd29a.1619594713.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

serial: 8250: Use 'hlist_for_each_entry' to simplify code

Use 'hlist_for_each_entry' instead of hand writing it.
This saves a few lines of code.

The comment about warning generated by some gcc version is also removed.
The way 'hlist_for_each_entry' is written should prevent such a warning to
be emitted.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/14024ddeb2b3a8c5b0138b5ba5083f54d00164a9.1619594713.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

serial: meson: remove redundant initialization of variable id

The variable id being initialized with a value that is never read
and it is being updated later with a new value. The initialization is
redundant and can be removed. Since id is just being used in a for-loop
inside a local scope, move the declaration of id to that scope.

Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Addresses-Coverity: ("Unused value")
Link: https://lore.kernel.org/r/20210426101106.9122-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

serial: 8250: of: Check for CONFIG_SERIAL_8250_BCM7271

Our SoC's have always had a NS16650A UART core and older SoC's would
have a compatible string of: 'compatible = ""ns16550a"' and use the
8250_of driver. Our newer SoC's have added enhancements to the base
core to add support for DMA and accurate high speed baud rates and use
this newer 8250_bcm7271 driver. The Device Tree node for our enhanced
UARTs has a compatible string of: 'compatible = "brcm,bcm7271-uart",
"ns16550a"''. With both drivers running and the link order setup so
that the 8250_bcm7217 driver is initialized before the 8250_of driver,
we should bind the 8250_bcm7271 driver to the enhanced UART, or for
upstream kernels that don't have the 8250_bcm7271 driver, we bind to
the 8250_of driver.

The problem is that when both the 8250_of and 8250_bcm7271 drivers
were running, occasionally the 8250_of driver would be bound to the
enhanced UART instead of the 8250_bcm7271 driver. This was happening
because we use SCMI based clocks which come up late in initialization
and cause probe DEFER's when the two drivers get their clocks.

Occasionally the SCMI clock would become ready between the 8250_bcm7271
probe and the 8250_of probe and the 8250_of driver would be bound. To
fix this we decided to config only our 8250_bcm7271 driver and added
"ns16665a0" to the compatible string so the driver would work on our
older system.

This commit has of_platform_serial_probe() check specifically for the
"brcm,bcm7271-uart" and whether its companion driver is enabled. If it
is the case, and the clock provider is not ready, we want to make sure
that when the 8250_bcm7271.c driver returns EPROBE_DEFER, we are not
getting the UART registered via 8250_of.c.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Jim Quinlan <jim2101024@gmail.com>
Signed-off-by: Al Cooper <alcooperx@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20210423183206.3917725-1-f.fainelli@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

serial: qcom_geni_serial: redundant initialization to variable line

The variable line being initialized with a value that is never read
and it is being updated later with a new value. The initialization is
redundant and can be removed.

Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Addresses-Coverity: ("Unused value")
Link: https://lore.kernel.org/r/20210423081317.318352-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

dt-bindings: serial: Add label property in serial.yaml

When there is more than one serial port present, the property 'label'
allows a custom name to be used for briefly describe the usage or position
of each serial port.

Without this "label" property, many dtbs_check warnings similar to the
following are reported:
arch/arm64/boot/dts/hisilicon/hi3660-hikey960.dt.yaml: \
serial@ffd74000: Additional properties are not allowed ('label' was unexpected)
        From schema: Documentation/devicetree/bindings/serial/pl011.yaml

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Link: https://lore.kernel.org/r/20210506132049.1513-3-thunder.leizhen@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

dt-bindings: serial: Change to reference the kernel-defined serial.yaml

The /schemas/serial.yaml from dt-schema only has the property $nodename,
whereas the kernel-defined /schemas/serial/serial.yaml contains more
useful properties, support for more complex application scenarios.

For example:
1) The property "current-speed" in fsl-lx2160a.dtsi
2) The subnode "bluetooth" in hi3660-hikey960.dts

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Link: https://lore.kernel.org/r/20210506132049.1513-2-thunder.leizhen@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

serial: 8250_aspeed_vuart: use UPF_IOREMAP to set up register mapping

Previously this driver's use of devm_ioremap_resource() led to
duplicated calls to __release_region() when unbinding it (one from
serial8250_release_std_resource() and one from devres_release_all()),
the second of which resulted in a warning message:

  # echo 1e787000.serial > /sys/bus/platform/drivers/aspeed-vuart/unbind
  [33091.774200] Trying to free nonexistent resource <000000001e787000-000000001e78703f>

With this change the driver uses the generic serial8250 code's
UPF_IOREMAP to take care of the register mapping automatically instead
of doing its own devm_ioremap_resource(), thus avoiding the duplicate
__release_region() on unbind.

In doing this we eliminate vuart->regs, since it merely duplicates
vuart->port->port.membase, which we now use for our I/O accesses.

Reported-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Link: https://lore.kernel.org/r/20210510014231.647-4-zev@bewilderbeest.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

serial: 8250_aspeed_vuart: initialize vuart->port in aspeed_vuart_probe()

Previously this had only been initialized if we hit the throttling path
in aspeed_vuart_handle_irq(); moving it to the probe function is a
slight consistency improvement and avoids redundant reinitialization in
the interrupt handler.  It also serves as preparation for converting the
driver's I/O accesses to use port->port.membase instead of its own
vuart->regs.

Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Link: https://lore.kernel.org/r/20210510014231.647-3-zev@bewilderbeest.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

serial: 8250_aspeed_vuart: factor out aspeed_vuart_{read, write}b() helper functions

This is a small prepatory step for changing the way this driver does
its I/O accesses.

Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Link: https://lore.kernel.org/r/20210510014231.647-2-zev@bewilderbeest.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: serial: samsung_tty: remove set but not used variables

The value of 'ret' is not used which reported by svace, so just return
instead of break.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Link: https://lore.kernel.org/r/1619484575-26098-1-git-send-email-tiantao6@hisilicon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

serial: fsl_lpuart: disable DMA for console and fix sysrq

SYSRQ doesn't work with DMA. This is because there is no error
indication whether a symbol had a framing error or not. Actually,
this is not completely correct, there is a bit in the data register
which is set in this case, but we'd have to read change the DMA access
to 16 bit and we'd need to post process the data, thus make the DMA
pointless in the first place.

Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20210512141255.18277-10-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

serial: fsl_lpuart: add loopback support

The LPUART can loop the RX and TX signal. Add support for it.

Please note, this was only tested on the 32 bit version of the LPUART.

Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20210512141255.18277-9-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

serial: fsl_lpuart: remove manual RTSCTS control from 8-bit LPUART

The LPUART doesn't have the ability to control the RTS or CTS line
manually. Instead it will set it automatically when data is send or
handle it when data is received. Thus drop the wrong code in set_mctrl.
For the 32 bit version this was already done in the commit 2b30efe2e88a
("tty: serial: lpuart: Remove unnecessary code from set_mctrl"). Keep
the 8-bit version in sync and remove it there, too.

Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20210512141255.18277-8-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

serial: fsl_lpuart: remove RTSCTS handling from get_mctrl()

The wrong code in set_mctrl() was already removed in commit 2b30efe2e88a
("tty: serial: lpuart: Remove unnecessary code from set_mctrl"), but the
code in get_mctrl() wasn't removed. It will not return the state of the
RTS or CTS line but whether automatic flow control is enabled, which is
wrong for the get_mctrl(). Thus remove it.

Fixes: 2b30efe2e88a ("tty: serial: lpuart: Remove unnecessary code from set_mctrl")
Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20210512141255.18277-7-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

serial: fsl_lpuart: handle break and make sysrq work

Although there is already sysrq characters handling, a break condition
was never detected. Add support for it.

The LPUART can't distinguish between a framing error and a break
condition. We assume it is a break if the received data is all zero.

Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20210512141255.18277-6-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

serial: fsl_lpuart: split sysrq handling

Instead of uart_handle_sysrq_char() use uart_prepare_sysrq_char() and
uart_unlock_and_check_sysrq(). This will call handle_sysrq() without
holding the port lock, which in turn let us drop the spin_trylock hack.

Suggested-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20210512141255.18277-5-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

serial: fsl_lpuart: don't restore interrupt state in ISR

>From commit 75f4e830fa9c ("serial: do not restore interrupt state in
sysrq helper"):

  Since commit 81e2073c175b ("genirq: Disable interrupts for force
  threaded handlers") interrupt handlers that are not explicitly
  requested as threaded are always called with interrupts disabled and
  there is no need to save the interrupt state when taking the port
  lock.

Apply this also to fsl_lpuart in prepartion for sysrq handling with
uart_unlock_and_check_sysrq().

Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20210512141255.18277-4-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

serial: fsl_lpuart: use UARTDATA_MASK macro

Use the corresponding macro instead of the magic number. While at it,
drop the useless cast to "unsigned char".

Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20210512141255.18277-3-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

serial: fsl_lpuart: don't modify arbitrary data on lpuart32

lpuart_rx_dma_startup() is used for both the 8 bit and the 32 bit
version of the LPUART. Modify the UARTCR only for the 8 bit version.

Fixes: f4eef224a09f ("serial: fsl_lpuart: add sysrq support when using dma")
Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20210512141255.18277-2-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tty: serial: fsl_lpuart: fix the potential risk of division or modulo by zero

We should be very careful about the register values that will be used
for division or modulo operations, althrough the possibility that the
UARTBAUD register value is zero is very low, but we had better to deal
with the "bad data" of hardware in advance to avoid division or modulo
by zero leading to undefined kernel behavior.

Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20210427021226.27468-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

dt-bindings: serial: snps-dw-apb-uart: add description for rk3568

add "rockchip,rk3568-uart", "snps,dw-apb-uart" for uart nodes on
a rk3568 platform to snps-dw-apb-uart.yaml.

Signed-off-by: Liang Chen <cl@rock-chips.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210429081151.17558-3-cl@rock-chips.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Linux 5.13-rc1

fbmem: fix horribly incorrect placement of __maybe_unused

Commit b9d79e4ca4ff ("fbmem: Mark proc_fb_seq_ops as __maybe_unused")
places the '__maybe_unused' in an entirely incorrect location between
the "struct" keyword and the structure name.

It's a wonder that gcc accepts that silently, but clang quite reasonably
warns about it:

    drivers/video/fbdev/core/fbmem.c:736:21: warning: attribute declaration must precede definition [-Wignored-attributes]
    static const struct __maybe_unused seq_operations proc_fb_seq_ops = {
                        ^

Fix it.

Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'drm-next-2021-05-10' of git://anongit.freedesktop.org/drm/drm

Pull drm fixes from Dave Airlie:
 "Bit later than usual, I queued them all up on Friday then promptly
  forgot to write the pull request email. This is mainly amdgpu fixes,
  with some radeon/msm/fbdev and one i915 gvt fix thrown in.

  amdgpu:
   - MPO hang workaround
   - Fix for concurrent VM flushes on vega/navi
   - dcefclk is not adjustable on navi1x and newer
   - MST HPD debugfs fix
   - Suspend/resumes fixes
   - Register VGA clients late in case driver fails to load
   - Fix GEM leak in user framebuffer create
   - Add support for polaris12 with 32 bit memory interface
   - Fix duplicate cursor issue when using overlay
   - Fix corruption with tiled surfaces on VCN3
   - Add BO size and stride check to fix BO size verification

  radeon:
   - Fix off-by-one in power state parsing
   - Fix possible memory leak in power state parsing

  msm:
   - NULL ptr dereference fix

  fbdev:
   - procfs disabled warning fix

  i915:
   - gvt: Fix a possible division by zero in vgpu display rate
     calculation"

* tag 'drm-next-2021-05-10' of git://anongit.freedesktop.org/drm/drm:
  drm/amdgpu: Use device specific BO size & stride check.
  drm/amdgpu: Init GFX10_ADDR_CONFIG for VCN v3 in DPG mode.
  drm/amd/pm: initialize variable
  drm/radeon: Avoid power table parsing memory leaks
  drm/radeon: Fix off-by-one power_state index heap overwrite
  drm/amd/display: Fix two cursor duplication when using overlay
  drm/amdgpu: add new MC firmware for Polaris12 32bit ASIC
  fbmem: Mark proc_fb_seq_ops as __maybe_unused
  drm/msm/dpu: Delete bonkers code
  drm/i915/gvt: Prevent divided by zero when calculating refresh rate
  amdgpu: fix GEM obj leak in amdgpu_display_user_framebuffer_create
  drm/amdgpu: Register VGA clients after init can no longer fail
  drm/amdgpu: Handling of amdgpu_device_resume return value for graceful teardown
  drm/amdgpu: fix r initial values
  drm/amd/display: fix wrong statement in mst hpd debugfs
  amdgpu/pm: set pp_dpm_dcefclk to readonly on NAVI10 and newer gpus
  amdgpu/pm: Prevent force of DCEFCLK on NAVI10 and SIENNA_CICHLID
  drm/amdgpu: fix concurrent VM flushes on Vega/Navi v2
  drm/amd/display: Reject non-zero src_y and src_x for video planes

Merge tag 'block-5.13-2021-05-09' of git://git.kernel.dk/linux-block

Pull block fix from Jens Axboe:
 "Turns out the bio max size change still has issues, so let's get it
  reverted for 5.13-rc1. We'll shake out the issues there and defer it
  to 5.14 instead"

* tag 'block-5.13-2021-05-09' of git://git.kernel.dk/linux-block:
  Revert "bio: limit bio max size"

Merge tag '5.13-rc-smb3-part3' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:
 "Three small SMB3 chmultichannel related changesets (also for stable)
  from the SMB3 test event this week.

  The other fixes are still in review/testing"

* tag '5.13-rc-smb3-part3' of git://git.samba.org/sfrench/cifs-2.6:
  smb3: if max_channels set to more than one channel request multichannel
  smb3: do not attempt multichannel to server which does not support it
  smb3: when mounting with multichannel include it in requested capabilities

Merge tag 'sched-urgent-2021-05-09' of git://git./linux/kernel/git/tip/tip

Pull scheduler fixes from Thomas Gleixner:
 "A set of scheduler updates:

   - Prevent PSI state corruption when schedule() races with cgroup
     move.

     A recent commit combined two PSI callbacks to reduce the number of
     cgroup tree updates, but missed that schedule() can drop rq::lock
     for load balancing, which opens the race window for
     cgroup_move_task() which then observes half updated state.

     The fix is to solely use task::ps_flags instead of looking at the
     potentially mismatching scheduler state

   - Prevent an out-of-bounds access in uclamp caused bu a rounding
     division which can lead to an off-by-one error exceeding the
     buckets array size.

   - Prevent unfairness caused by missing load decay when a task is
     attached to a cfs runqueue.

     The old load of the task was attached to the runqueue and never
     removed. Fix it by enforcing the load update through the hierarchy
     for unthrottled run queue instances.

   - A documentation fix fot the 'sched_verbose' command line option"

* tag 'sched-urgent-2021-05-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Fix unfairness caused by missing load decay
  sched: Fix out-of-bound access in uclamp
  psi: Fix psi state corruption when schedule() races with cgroup move
  sched,doc: sched_debug_verbose cmdline should be sched_verbose

Merge tag 'locking-urgent-2021-05-09' of git://git./linux/kernel/git/tip/tip

Pull locking fixes from Thomas Gleixner:
 "A set of locking related fixes and updates:

   - Two fixes for the futex syscall related to the timeout handling.

     FUTEX_LOCK_PI does not support the FUTEX_CLOCK_REALTIME bit and
     because it's not set the time namespace adjustment for clock
     MONOTONIC is applied wrongly.

     FUTEX_WAIT cannot support the FUTEX_CLOCK_REALTIME bit because its
     always a relative timeout.

   - Cleanups in the futex syscall entry points which became obvious
     when the two timeout handling bugs were fixed.

   - Cleanup of queued_write_lock_slowpath() as suggested by Linus

   - Fixup of the smp_call_function_single_async() prototype"

* tag 'locking-urgent-2021-05-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Make syscall entry points less convoluted
  futex: Get rid of the val2 conditional dance
  futex: Do not apply time namespace adjustment on FUTEX_LOCK_PI
  Revert 337f13046ff0 ("futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op")
  locking/qrwlock: Cleanup queued_write_lock_slowpath()
  smp: Fix smp_call_function_single_async prototype