lib/vsprintf: Remove atomic-unsafe support for %pCr

commit 666902e42fd8344b923c02dc5b0f37948ff4f225 upstream.

"%pCr" formats the current rate of a clock, and calls clk_get_rate().
The latter obtains a mutex, hence it must not be called from atomic
context.

Remove support for this rarely-used format, as vsprintf() (and e.g.
printk()) must be callable from any context.

Any remaining out-of-tree users will start seeing the clock's name
printed instead of its rate.

Reported-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Fixes: 900cca2944254edd ("lib/vsprintf: add %pC{,n,r} format specifiers for clocks")
Link: http://lkml.kernel.org/r/1527845302-12159-5-git-send-email-geert+renesas@glider.be
To: Jia-Ju Bai <baijiaju1990@gmail.com>
To: Jonathan Corbet <corbet@lwn.net>
To: Michael Turquette <mturquette@baylibre.com>
To: Stephen Boyd <sboyd@kernel.org>
To: Zhang Rui <rui.zhang@intel.com>
To: Eduardo Valentin <edubezval@gmail.com>
To: Eric Anholt <eric@anholt.net>
To: Stefan Wahren <stefan.wahren@i2se.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-clk@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: linux-serial@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-renesas-soc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: stable@vger.kernel.org # 4.1+
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
index 361789d..d1aecf5 100644 (file)
--- a/Documentation/printk-formats.txt
+++ b/Documentation/printk-formats.txt
@@ -397,11 +397,10 @@ struct clk
 
        %pC     pll1
        %pCn    pll1
-       %pCr    1560000000
 
 For printing struct clk structures. ``%pC`` and ``%pCn`` print the name
 (Common Clock Framework) or address (legacy clock framework) of the
-structure; ``%pCr`` prints the current clock rate.
+structure.
 
 Passed by reference.
 

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 86c3385..4a990f3 100644 (file)
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1392,9 +1392,6 @@ char *clock(char *buf, char *end, struct clk *clk, struct printf_spec spec,
                return string(buf, end, NULL, spec);
 
        switch (fmt[1]) {
-       case 'r':
-               return number(buf, end, clk_get_rate(clk), spec);
-
        case 'n':
        default:
 #ifdef CONFIG_COMMON_CLK