[PATCH v3 2/2] PM / Sleep: fix recovery during resuming from hibernation

From: Imre Deak
Date: Fri Oct 24 2014 - 13:31:23 EST


If a device's dev_pm_ops::freeze callback fails during the QUIESCE
phase we don't rollback things correctly calling the thaw and complete
callbacks. This could leave some devices in a suspended state in case of
an error during resuming from hibernation.

v2:
- call dpm_resume_end() unconditionally, it's guaranteed that error
is non-zero
v3:
- split out this fix into a separate patch (Rafael)
- add code comment on why BUG_ON() is used (Rafael)

Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
---
kernel/power/hibernate.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
index a9dfa79..1f35a34 100644
--- a/kernel/power/hibernate.c
+++ b/kernel/power/hibernate.c
@@ -502,8 +502,14 @@ int hibernation_restore(int platform_mode)
error = dpm_suspend_start(PMSG_QUIESCE);
if (!error) {
error = resume_target_kernel(platform_mode);
- dpm_resume_end(PMSG_RECOVER);
+ /*
+ * The above should either succeed and jump to the new kernel,
+ * or return with an error. Otherwise things are just
+ * undefined, so let's be paranoid.
+ */
+ BUG_ON(!error);
}
+ dpm_resume_end(PMSG_RECOVER);
pm_restore_gfp_mask();
resume_console();
pm_restore_console();
--
1.8.4

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