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| author | Rafael J. Wysocki <rjw@sisk.pl> | 2010-09-22 22:10:57 +0200 |
|---|---|---|
| committer | Rafael J. Wysocki <rjw@sisk.pl> | 2010-10-17 01:57:43 +0200 |
| commit | 098dff738abbeaea15fc95c4f4fdaee1e9bbea75 (patch) | |
| tree | b2282f59358b4f1e8bbf9949ff1eec4c8016ca5f /include/linux | |
| parent | 074037ec79bea73edf1b1ec72fef1010e83e3cc5 (diff) | |
| download | linux-stable-098dff738abbeaea15fc95c4f4fdaee1e9bbea75.tar.gz linux-stable-098dff738abbeaea15fc95c4f4fdaee1e9bbea75.tar.bz2 linux-stable-098dff738abbeaea15fc95c4f4fdaee1e9bbea75.zip | |
PM: Fix potential issue with failing asynchronous suspend
There is a potential issue with the asynchronous suspend code that
a device driver suspending asynchronously may not notice that it
should back off. There are two failing scenarions, (1) when the
driver is waiting for a driver suspending synchronously to complete
and that second driver returns error code, in which case async_error
won't be set and the waiting driver will continue suspending and (2)
after the driver has called device_pm_wait_for_dev() and the waited
for driver returns error code, in which case the caller of
device_pm_wait_for_dev() will not know that there was an error and
will continue suspending.
To fix this issue make __device_suspend() set async_error, so
async_suspend() doesn't need to set it any more, and make
device_pm_wait_for_dev() return async_error, so that its callers
can check whether or not they should continue suspending.
No more changes are necessary, since device_pm_wait_for_dev() is
not used by any drivers' suspend routines.
Reported-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/pm.h | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/include/linux/pm.h b/include/linux/pm.h index a84118911ced..1abfe84f447d 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -559,7 +559,7 @@ extern void __suspend_report_result(const char *function, void *fn, int ret); __suspend_report_result(__func__, fn, ret); \ } while (0) -extern void device_pm_wait_for_dev(struct device *sub, struct device *dev); +extern int device_pm_wait_for_dev(struct device *sub, struct device *dev); #else /* !CONFIG_PM_SLEEP */ #define device_pm_lock() do {} while (0) @@ -572,7 +572,10 @@ static inline int dpm_suspend_start(pm_message_t state) #define suspend_report_result(fn, ret) do {} while (0) -static inline void device_pm_wait_for_dev(struct device *a, struct device *b) {} +static inline int device_pm_wait_for_dev(struct device *a, struct device *b) +{ + return 0; +} #endif /* !CONFIG_PM_SLEEP */ /* How to reorder dpm_list after device_move() */ |