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authorRafael J. Wysocki <rjw@sisk.pl>2010-09-23 00:10:57 +0400
committerRafael J. Wysocki <rjw@sisk.pl>2010-10-17 03:57:43 +0400
commit098dff738abbeaea15fc95c4f4fdaee1e9bbea75 (patch)
treeb2282f59358b4f1e8bbf9949ff1eec4c8016ca5f /include/linux/pm.h
parent074037ec79bea73edf1b1ec72fef1010e83e3cc5 (diff)
downloadlinux-098dff738abbeaea15fc95c4f4fdaee1e9bbea75.tar.xz
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/pm.h')
-rw-r--r--include/linux/pm.h7
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() */