Re: [PATCH v7 1/8] scsi: ufs: Add checks before setting clk-gating states

[Stanley Chu]

On Tue, 2020-07-28 at 13:00 +0800, Can Guo wrote:
> 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 
> Reviewed-by: Avri Altman 
> Reviewed-by: Hongwu Su 

Reviewed-by: Stanley Chu 

[PATCH v7 1/8] scsi: ufs: Add checks before setting clk-gating states

[Can Guo]

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 
Reviewed-by: Avri Altman 
Reviewed-by: Hongwu Su 
---
 drivers/scsi/ufs/ufshcd.c | 17 ++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index cdff7e5..99bd3e4 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(>clk_gating.gate_work, ufshcd_gate_work);
INIT_WORK(>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 = >lrb[tag];
 
@@ -8315,8 +8318,11 @@ 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);
@@ -8456,6 +8462,11 @@ 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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