[PATCH 4/4] lib/vsprintf: Remove atomic-unsafe support for %pCr

From: Geert Uytterhoeven
Date: Fri Jun 01 2018 - 05:29:27 EST


"%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@xxxxxxxxx>
Fixes: 900cca2944254edd ("lib/vsprintf: add %pC{,n,r} format specifiers for clocks")
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
Documentation/core-api/printk-formats.rst | 3 +--
lib/vsprintf.c | 3 ---
2 files changed, 1 insertion(+), 5 deletions(-)

diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst
index eb30efdd2e789616..25dc591cb1108790 100644
--- a/Documentation/core-api/printk-formats.rst
+++ b/Documentation/core-api/printk-formats.rst
@@ -419,11 +419,10 @@ 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 247a7e0bf24f6f74..a48aaa79d352313a 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -1469,9 +1469,6 @@ 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
--
2.7.4