[PATCH 1/9] scsi: ufs: Add checks before setting clk-gating states

From: Can Guo
Date: Thu Aug 06 2020 - 01:07:26 EST


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

Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
Reviewed-by: Avri Altman <avri.altman@xxxxxxx>
Reviewed-by: Hongwu Su <hongwus@xxxxxxxxxxxxxx>
Reviewed-by: Stanley Chu <stanley.chu@xxxxxxxxxxxx>
Reviewed-by: Bean Huo <beanhuo@xxxxxxxxxx>

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 3076222..5acb38c 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/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)
--
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