[PATCH] scsi: ufs: qcom: avoid re-init quirk when gears match

[Eric Chanudet <echanude@redhat.com>]

On sa8775p-ride, probing the hba will go through the
UFSHCD_QUIRK_REINIT_AFTER_MAX_GEAR_SWITCH path although the power info
are same during the second init.

If the host is at least v4, ufs_qcom_get_hs_gear() picked the highest
supported gear when setting the host_params. After the negotiation, if
the host and device are on the same gear, it is the highest gear
supported between the two. Skip the re-init to save some time.

Signed-off-by: Eric Chanudet <echanude@redhat.com>
---

"trace_event=ufs:ufshcd_init" reports the time spent where the re-init
quirk is performed. On sa8775p-ride:
Baseline:
  0.355879: ufshcd_init: 1d84000.ufs: took 103377 usecs, dev_state: UFS_ACTIVE_PWR_MODE, link_state: UIC_LINK_ACTIVE_STATE, err 0
With this patch:
  0.297676: ufshcd_init: 1d84000.ufs: took 43553 usecs, dev_state: UFS_ACTIVE_PWR_MODE, link_state: UIC_LINK_ACTIVE_STATE, err 0

 drivers/ufs/host/ufs-qcom.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
index 39eef470f8fa..f9f161340e78 100644
--- a/drivers/ufs/host/ufs-qcom.c
+++ b/drivers/ufs/host/ufs-qcom.c
@@ -738,8 +738,12 @@ static int ufs_qcom_pwr_change_notify(struct ufs_hba *hba,
 		 * the second init can program the optimal PHY settings. This allows one to start
 		 * the first init with either the minimum or the maximum support gear.
 		 */
-		if (hba->ufshcd_state == UFSHCD_STATE_RESET)
+		if (hba->ufshcd_state == UFSHCD_STATE_RESET) {
+			if (host->hw_ver.major >= 0x4 &&
+			    host_params->hs_tx_gear == dev_req_params->gear_tx)
+				hba->quirks &= ~UFSHCD_QUIRK_REINIT_AFTER_MAX_GEAR_SWITCH;
 			host->phy_gear = dev_req_params->gear_tx;
+		}
 
 		/* enable the device ref clock before changing to HS mode */
 		if (!ufshcd_is_hs_mode(&hba->pwr_info) &&
-- 
2.43.0