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| author | Wolfram Sang <w.sang@pengutronix.de> | 2011-01-12 17:00:23 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-13 08:03:14 -0800 |
| commit | 0fdae42d361bbb431ca0ab0efed5126a94821177 (patch) | |
| tree | 958a045aca3e40ca487dac67597496a7ed885115 /Documentation/gpio.txt | |
| parent | 49a367937fe4250144e24440e5a11ae4344202b1 (diff) | |
| download | lwn-0fdae42d361bbb431ca0ab0efed5126a94821177.tar.gz lwn-0fdae42d361bbb431ca0ab0efed5126a94821177.zip | |
gpiolib: annotate gpio-intialization with __must_check
Because GPIOs can have crucial functions especially in embedded systems,
we are better safe than sorry regarding their configuration. For
gpio_request, the documentation is simply enforced: <quote>"The return
value of gpio_request() must be checked."</quote> For gpio_direction_* and
gpio_request_*, we now act accordingly.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Greg KH <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/gpio.txt')
| -rw-r--r-- | Documentation/gpio.txt | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/Documentation/gpio.txt b/Documentation/gpio.txt index 792faa3c06cf..a492d92bb098 100644 --- a/Documentation/gpio.txt +++ b/Documentation/gpio.txt @@ -135,7 +135,7 @@ setting up a platform_device using the GPIO, is mark its direction: int gpio_direction_input(unsigned gpio); int gpio_direction_output(unsigned gpio, int value); -The return value is zero for success, else a negative errno. It should +The return value is zero for success, else a negative errno. It must be checked, since the get/set calls don't have error returns and since misconfiguration is possible. You should normally issue these calls from a task context. However, for spinlock-safe GPIOs it's OK to use them |