scsi: ufs: host: mediatek: Fix PWM mode switch issue

Address a failure in switching to PWM mode by ensuring proper
configuration of power modes and adaptation settings. The changes
include checks for SLOW_MODE and adjustments to the desired working mode
and adaptation configuration based on the device's power mode and
hardware version.

Signed-off-by: Peter Wang <peter.wang@mediatek.com>
Link: https://lore.kernel.org/r/20250811131423.3444014-6-peter.wang@mediatek.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Author: ptr324

drivers/ufs/host/ufs-mediatek.c

@@ -1321,6 +1321,10 @@ static bool ufs_mtk_pmc_via_fastauto(struct ufs_hba *hba,
 	    dev_req_params->gear_rx < UFS_HS_G4)
 		return false;
 
+	if (dev_req_params->pwr_tx == SLOW_MODE ||
+	    dev_req_params->pwr_rx == SLOW_MODE)
+		return false;
+
 	return true;
 }
 
@@ -1336,6 +1340,10 @@ static int ufs_mtk_pre_pwr_change(struct ufs_hba *hba,
 	host_params.hs_rx_gear = UFS_HS_G5;
 	host_params.hs_tx_gear = UFS_HS_G5;
 
+	if (dev_max_params->pwr_rx == SLOW_MODE ||
+	    dev_max_params->pwr_tx == SLOW_MODE)
+		host_params.desired_working_mode = UFS_PWM_MODE;
+
 	ret = ufshcd_negotiate_pwr_params(&host_params, dev_max_params, dev_req_params);
 	if (ret) {
 		pr_info("%s: failed to determine capabilities\n",
@@ -1368,10 +1376,21 @@ static int ufs_mtk_pre_pwr_change(struct ufs_hba *hba,
 		}
 	}
 
-	if (host->hw_ver.major >= 3) {
+	if (dev_req_params->pwr_rx == FAST_MODE ||
+	    dev_req_params->pwr_rx == FASTAUTO_MODE) {
+		if (host->hw_ver.major >= 3) {
+			ret = ufshcd_dme_configure_adapt(hba,
+						   dev_req_params->gear_tx,
+						   PA_INITIAL_ADAPT);
+		} else {
+			ret = ufshcd_dme_configure_adapt(hba,
+				   dev_req_params->gear_tx,
+				   PA_NO_ADAPT);
+		}
+	} else {
 		ret = ufshcd_dme_configure_adapt(hba,
-					   dev_req_params->gear_tx,
-					   PA_INITIAL_ADAPT);
+			   dev_req_params->gear_tx,
+			   PA_NO_ADAPT);
 	}
 
 	return ret;