[PATCH] scsi: ufs: core: Do not set link to OFF state while waking up from hibernation

[PATCH] scsi: ufs: core: Do not set link to OFF state while waking up from hibernation

[Manivannan Sadhasivam]

UFS link is just put into hibern8 state during the 'freeze' process of the
hibernation. Afterwards, the system may get powered down. But that doesn't
matter during wakeup. Because during wakeup from hibernation, UFS link is
again put into hibern8 state by the restore kernel and then the control is
handed over to the to image kernel.

So in both the places, UFS link is never turned OFF. But
ufshcd_system_restore() just assumes that the link will be in OFF state and
sets the link state accordingly. And this breaks hibernation wakeup:

[ 2445.371335] phy phy-1d87000.phy.3: phy_power_on was called before phy_init
[ 2445.427883] ufshcd-qcom 1d84000.ufshc: Controller enable failed
[ 2445.427890] ufshcd-qcom 1d84000.ufshc: ufshcd_host_reset_and_restore: Host init failed -5
[ 2445.427906] ufs_device_wlun 0:0:0:49488: ufshcd_wl_resume failed: -5
[ 2445.427918] ufs_device_wlun 0:0:0:49488: PM: dpm_run_callback(): scsi_bus_restore returns -5
[ 2445.427973] ufs_device_wlun 0:0:0:49488: PM: failed to restore async: error -5

So fix the issue by removing the code that sets the link to OFF state.

Cc: Anjana Hari <quic_ahari@quicinc.com>
Cc: stable@vger.kernel.org # 6.3
Fixes: 88441a8d355d ("scsi: ufs: core: Add hibernation callbacks")
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/ufs/core/ufshcd.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 9f037a40316a..a9dfa82adac9 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -10261,9 +10261,6 @@ int ufshcd_system_restore(struct device *dev)
 	 */
 	ufshcd_readl(hba, REG_UTP_TASK_REQ_LIST_BASE_H);
 
-	/* Resuming from hibernate, assume that link was OFF */
-	ufshcd_set_link_off(hba);
-
 	return 0;
 
 }
-- 
2.25.1

Re: [PATCH] scsi: ufs: core: Do not set link to OFF state while waking up from hibernation

[Bart Van Assche]

On 7/18/24 10:06 AM, Manivannan Sadhasivam wrote:
> UFS link is just put into hibern8 state during the 'freeze' process of the
> hibernation. Afterwards, the system may get powered down. But that doesn't
> matter during wakeup. Because during wakeup from hibernation, UFS link is
> again put into hibern8 state by the restore kernel and then the control is
> handed over to the to image kernel.
> 
> So in both the places, UFS link is never turned OFF. But
> ufshcd_system_restore() just assumes that the link will be in OFF state and
> sets the link state accordingly. And this breaks hibernation wakeup:

Reviewed-by: Bart Van Assche <bvanassche@acm.org>

Re: [PATCH] scsi: ufs: core: Do not set link to OFF state while waking up from hibernation

[Martin K. Petersen]

Manivannan,

> UFS link is just put into hibern8 state during the 'freeze' process of
> the hibernation. Afterwards, the system may get powered down. But that
> doesn't matter during wakeup. Because during wakeup from hibernation,
> UFS link is again put into hibern8 state by the restore kernel and
> then the control is handed over to the to image kernel.

Applied to 6.11/scsi-staging, thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering