6.6-stable review patch. If anyone has any objections, please let me know.
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From: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org
commit fc88ca19ad0989dc0e4d4b126d5d0ba91f6cb616 upstream.
The "hs_gear" variable is used to program the PHY settings (submode) during ufs_qcom_power_up_sequence(). Currently, it is being updated every time the agreed gear changes. Due to this, if the gear got downscaled before suspend (runtime/system), then while resuming, the PHY settings for the lower gear will be applied first and later when scaling to max gear with REINIT, the PHY settings for the max gear will be applied.
This adds a latency while resuming and also really not needed as the PHY gear settings are backwards compatible i.e., we can continue using the PHY settings for max gear with lower gear speed.
So let's update the "hs_gear" variable _only_ when the agreed gear is greater than the current one. This guarantees that the PHY settings will be changed only during probe time and fatal error condition.
Due to this, UFSHCD_QUIRK_REINIT_AFTER_MAX_GEAR_SWITCH can now be skipped when the PM operation is in progress.
Cc: stable@vger.kernel.org Fixes: 96a7141da332 ("scsi: ufs: core: Add support for reinitializing the UFS device") Reported-by: Can Guo quic_cang@quicinc.com Signed-off-by: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org Link: https://lore.kernel.org/r/20230908145329.154024-1-manivannan.sadhasivam@lina... Reviewed-by: Can Guo quic_cang@quicinc.com Tested-by: Can Guo quic_cang@quicinc.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/ufs/core/ufshcd.c | 3 ++- drivers/ufs/host/ufs-qcom.c | 9 +++++++-- 2 files changed, 9 insertions(+), 3 deletions(-)
--- a/drivers/ufs/core/ufshcd.c +++ b/drivers/ufs/core/ufshcd.c @@ -8723,7 +8723,8 @@ static int ufshcd_probe_hba(struct ufs_h if (ret) goto out;
- if (hba->quirks & UFSHCD_QUIRK_REINIT_AFTER_MAX_GEAR_SWITCH) { + if (!hba->pm_op_in_progress && + (hba->quirks & UFSHCD_QUIRK_REINIT_AFTER_MAX_GEAR_SWITCH)) { /* Reset the device and controller before doing reinit */ ufshcd_device_reset(hba); ufshcd_hba_stop(hba); --- a/drivers/ufs/host/ufs-qcom.c +++ b/drivers/ufs/host/ufs-qcom.c @@ -909,8 +909,13 @@ static int ufs_qcom_pwr_change_notify(st return ret; }
- /* Use the agreed gear */ - host->hs_gear = dev_req_params->gear_tx; + /* + * Update hs_gear only when the gears are scaled to a higher value. This is because, + * the PHY gear settings are backwards compatible and we only need to change the PHY + * settings while scaling to higher gears. + */ + if (dev_req_params->gear_tx > host->hs_gear) + host->hs_gear = dev_req_params->gear_tx;
/* enable the device ref clock before changing to HS mode */ if (!ufshcd_is_hs_mode(&hba->pwr_info) &&