gpio_free might sleep, generic part

According to the documentation gpio_free should only be called from task
context only.  To make this more explicit add a might sleep to all
implementations.

This is the generic part which changes gpiolib and the fallback
implementation only.

Signed-off-by: Uwe Kleine-König <ukleinek@informatik.uni-freiburg.de>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/linux/gpio.h b/include/linux/gpio.h
index 730a20b83576..e10c49a5b96e 100644
--- a/include/linux/gpio.h
+++ b/include/linux/gpio.h
@@ -8,6 +8,7 @@
 
 #else
 
+#include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/errno.h>
 
@@ -32,6 +33,8 @@ static inline int gpio_request(unsigned gpio, const char *label)
 
 static inline void gpio_free(unsigned gpio)
 {
+        might_sleep();
+
         /* GPIO can never have been requested */
         WARN_ON(1);
 }