Revert "serial: uart: add hw flow control support configuration"
authorPeter Hurley <peter@hurleysoftware.com>
Tue, 2 Sep 2014 21:39:10 +0000 (17:39 -0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 8 Sep 2014 23:21:35 +0000 (16:21 -0700)
commita6eec92ec0815ce8ce57e4746e9f717d4146d869
tree1362131aff20ceb27fb8575d26a30ff081f3c28c
parent95562e7fdfe3fae2a10bb7ab16fc1260fe8dd810
Revert "serial: uart: add hw flow control support configuration"

This reverts commit 06aa82e498c144c7784a6f3d3b55458b272d6146.
This commit purports to enable auto CTS flow control for the 8250
UART driver. However, the 8250 UART driver already supports auto
CTS flow control via UART_CAP_AFE and UART_CAP_EFR. Indeed, this
patch introduces another DT attribute for which an existing firmware
flag already exists ("auto-flow-control"). Furthermore, the use of
UPF_HARD_FLOW requires the UART driver to define .throttle and
.unthrottle methods, neither of which are defined for the 8250 UART
driver (which will result in a NULL ptr dereference). Finally, this patch
supposes to fix existing bugs in the serial core for auto CTS-enabled
hardware, but does not include the class of hardware for which these
bugs exist.

CC: Murali Karicheri <m-karicheri2@ti.com>
CC: Rob Herring <robh+dt@kernel.org>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Documentation/devicetree/bindings/serial/of-serial.txt
drivers/tty/serial/8250/8250_core.c
drivers/tty/serial/of_serial.c
drivers/tty/serial/serial_core.c