This is a note to let you know that I've just added the patch titled
scsi: ufs: qcom: Update PHY settings only when scaling to higher gears
to the 6.5-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
scsi-ufs-qcom-update-phy-settings-only-when-scaling-to-higher-gears.patch
and it can be found in the queue-6.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From fc88ca19ad0989dc0e4d4b126d5d0ba91f6cb616 Mon Sep 17 00:00:00 2001
From: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
Date: Fri, 8 Sep 2023 20:23:28 +0530
Subject: scsi: ufs: qcom: Update PHY settings only when scaling to higher gears
From: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
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@xxxxxxxxxxxxxxx
Fixes: 96a7141da332 ("scsi: ufs: core: Add support for reinitializing the UFS device")
Reported-by: Can Guo <quic_cang@xxxxxxxxxxx>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230908145329.154024-1-manivannan.sadhasivam@xxxxxxxxxx
Reviewed-by: Can Guo <quic_cang@xxxxxxxxxxx>
Tested-by: Can Guo <quic_cang@xxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -8798,7 +8798,8 @@ 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
@@ -820,8 +820,13 @@ 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) &&
Patches currently in stable-queue which might be from manivannan.sadhasivam@xxxxxxxxxx are
queue-6.5/scsi-ufs-qcom-update-phy-settings-only-when-scaling-to-higher-gears.patch
queue-6.5/pci-dwc-add-missing-pci_exp_lnkcap_mlw-handling.patch
