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| author | Strashko, Grygorii <grygorii.strashko@ti.com> | 2015-11-10 10:42:34 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2015-11-30 14:47:22 +0100 |
| commit | 013c074f8642d8e815ad670601f8e27155a74b57 (patch) | |
| tree | 66eb244459aa071de90db3cb258370e7aeb1e910 /drivers/base/power/main.c | |
| parent | Linux 4.4-rc3 (diff) | |
| download | linux-013c074f8642d8e815ad670601f8e27155a74b57.tar.xz linux-013c074f8642d8e815ad670601f8e27155a74b57.zip | |
PM / sleep: prohibit devices probing during suspend/hibernation
It is unsafe [1] if probing of devices will happen during suspend or
hibernation and system behavior will be unpredictable in this case.
So, let's prohibit device's probing in dpm_prepare() and defer their
probing instead. The normal behavior will be restored in
dpm_complete().
This patch introduces new DD core APIs:
device_block_probing()
It will disable probing of devices and defer their probes instead.
device_unblock_probing()
It will restore normal behavior and trigger re-probing of deferred
devices.
[1] https://lkml.org/lkml/2015/9/11/554
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/base/power/main.c')
| -rw-r--r-- | drivers/base/power/main.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 1710c26ba097..9d626ac08d9c 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -963,6 +963,9 @@ void dpm_complete(pm_message_t state) } list_splice(&list, &dpm_list); mutex_unlock(&dpm_list_mtx); + + /* Allow device probing and trigger re-probing of deferred devices */ + device_unblock_probing(); trace_suspend_resume(TPS("dpm_complete"), state.event, false); } @@ -1624,6 +1627,20 @@ int dpm_prepare(pm_message_t state) trace_suspend_resume(TPS("dpm_prepare"), state.event, true); might_sleep(); + /* + * Give a chance for the known devices to complete their probes, before + * disable probing of devices. This sync point is important at least + * at boot time + hibernation restore. + */ + wait_for_device_probe(); + /* + * It is unsafe if probing of devices will happen during suspend or + * hibernation and system behavior will be unpredictable in this case. + * So, let's prohibit device's probing here and defer their probes + * instead. The normal behavior will be restored in dpm_complete(). + */ + device_block_probing(); + mutex_lock(&dpm_list_mtx); while (!list_empty(&dpm_list)) { struct device *dev = to_device(dpm_list.next); |