scsi: ufs: qcom: Update PHY settings only when scaling to higher gears

scsi: ufs: qcom: Update PHY settings only when scaling to higher gears

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@linaro.org
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>