scsi: ufs: Add checks before setting clk-gating states

Clock gating can be turned on/off selectively which means the associated
state information is only correct if the feature is enabled. This change
makes sure that we only look at state of clk-gating if it is enabled.

Link: https://lore.kernel.org/r/1596975355-39813-2-git-send-email-cang@codeaurora.orgReviewed-by: NAvri Altman <avri.altman@wdc.com>
Reviewed-by: NHongwu Su <hongwus@codeaurora.org>
Reviewed-by: NStanley Chu <stanley.chu@mediatek.com>
Reviewed-by: NBean Huo <beanhuo@micron.com>
Reviewed-by: NAsutosh Das <asutoshd@codeaurora.org>
Signed-off-by: NCan Guo <cang@codeaurora.org>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/ufs/ufshcd.c

@@ -1839,6 +1839,8 @@ static void ufshcd_init_clk_gating(struct ufs_hba *hba)
 	if (!ufshcd_is_clkgating_allowed(hba))
 		return;
 
+	hba->clk_gating.state = CLKS_ON;
+
 	hba->clk_gating.delay_ms = 150;
 	INIT_DELAYED_WORK(&hba->clk_gating.gate_work, ufshcd_gate_work);
 	INIT_WORK(&hba->clk_gating.ungate_work, ufshcd_ungate_work);
@@ -2541,7 +2543,8 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
 		err = SCSI_MLQUEUE_HOST_BUSY;
 		goto out;
 	}
-	WARN_ON(hba->clk_gating.state != CLKS_ON);
+	WARN_ON(ufshcd_is_clkgating_allowed(hba) &&
+		(hba->clk_gating.state != CLKS_ON));
 
 	lrbp = &hba->lrb[tag];
 
@@ -8326,8 +8329,11 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 		/* If link is active, device ref_clk can't be switched off */
 		__ufshcd_setup_clocks(hba, false, true);
 
-	hba->clk_gating.state = CLKS_OFF;
-	trace_ufshcd_clk_gating(dev_name(hba->dev), hba->clk_gating.state);
+	if (ufshcd_is_clkgating_allowed(hba)) {
+		hba->clk_gating.state = CLKS_OFF;
+		trace_ufshcd_clk_gating(dev_name(hba->dev),
+					hba->clk_gating.state);
+	}
 
 	/* Put the host controller in low power mode if possible */
 	ufshcd_hba_vreg_set_lpm(hba);
@@ -8467,6 +8473,11 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 	if (hba->clk_scaling.is_allowed)
 		ufshcd_suspend_clkscaling(hba);
 	ufshcd_setup_clocks(hba, false);
+	if (ufshcd_is_clkgating_allowed(hba)) {
+		hba->clk_gating.state = CLKS_OFF;
+		trace_ufshcd_clk_gating(dev_name(hba->dev),
+					hba->clk_gating.state);
+	}
 out:
 	hba->pm_op_in_progress = 0;
 	if (ret)