From: Stanley Chu stanley.chu@mediatek.com
[ Upstream commit e92643db514803c2c87d72caf5950b4c0a8faf4a ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/ufs/ufshcd.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index d7a0a64f64536..e37f6db0dd156 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -5387,11 +5387,7 @@ 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: