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authorStanley Chu <stanley.chu@mediatek.com>2020-11-19 14:29:16 +0800
committerMartin K. Petersen <martin.petersen@oracle.com>2020-11-19 22:18:36 -0500
commite92643db514803c2c87d72caf5950b4c0a8faf4a (patch)
treea9874702b7f0cb6e6d1b5a8a6165a3b385c499be /drivers/scsi/ufs
parent73cc291c270248567245f084dcdf5078069af6b5 (diff)
scsi: ufs: Fix race between shutdown and runtime resume flow
If UFS host device is in runtime-suspended state while UFS shutdown callback is invoked, UFS device shall be resumed for register accesses. Currently only UFS local runtime resume function will be invoked to wake up the host. This is not enough because if someone triggers runtime resume from block layer, then race may happen between shutdown and runtime resume flow, and finally lead to unlocked register access. To fix this, in ufshcd_shutdown(), use pm_runtime_get_sync() instead of resuming UFS device by ufshcd_runtime_resume() "internally" to let runtime PM framework manage the whole resume flow. Link: https://lore.kernel.org/r/20201119062916.12931-1-stanley.chu@mediatek.com Fixes: 57d104c153d3 ("ufs: add UFS power management support") Reviewed-by: Can Guo <cang@codeaurora.org> Signed-off-by: Stanley Chu <stanley.chu@mediatek.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi/ufs')
-rw-r--r--drivers/scsi/ufs/ufshcd.c6
1 files changed, 1 insertions, 5 deletions
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 20b16de4c5e2..0c148fcd24de 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -8913,11 +8913,7 @@ int ufshcd_shutdown(struct ufs_hba *hba)
if (ufshcd_is_ufs_dev_poweroff(hba) && ufshcd_is_link_off(hba))
goto out;
- if (pm_runtime_suspended(hba->dev)) {
- ret = ufshcd_runtime_resume(hba);
- if (ret)
- goto out;
- }
+ pm_runtime_get_sync(hba->dev);
ret = ufshcd_suspend(hba, UFS_SHUTDOWN_PM);
out: