[PATCH v1] scsi: ufs: Fix ufshcd_scale_clks decision in recovery flow

From: Stanley Chu
Date: Fri Jul 29 2022 - 03:55:40 EST


When someone toggles clk-scaling feature via sysfs interface,
the flag "hba->clk_scaling.is_enabled" shall be changed after
ufshcd_devfreq_scale() is finished.

By this change, we can use this flag to make right decision for
invoking ufshcd_scale_clks() in host recovery flow, i.e., in
ufshcd_host_reset_and_restore().

ufshcd_scale_clks() shall be invoked only if both conditions
are satisfied,

1. Clk-scaling is supported, and
2. Clk-scaling is enabled

Otherwise, the clk and gear which would be scaled by
ufshcd_scale_clks() shall be already in the default state
so the scaling is not required anymore.

Signed-off-by: Stanley Chu <stanley.chu@xxxxxxxxxxxx>
---
drivers/ufs/core/ufshcd.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 581d88af07ab..dc57a7988023 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -1574,8 +1574,6 @@ static ssize_t ufshcd_clkscale_enable_store(struct device *dev,
ufshcd_rpm_get_sync(hba);
ufshcd_hold(hba, false);

- hba->clk_scaling.is_enabled = value;
-
if (value) {
ufshcd_resume_clkscaling(hba);
} else {
@@ -1586,6 +1584,8 @@ static ssize_t ufshcd_clkscale_enable_store(struct device *dev,
__func__, err);
}

+ hba->clk_scaling.is_enabled = value;
+
ufshcd_release(hba);
ufshcd_rpm_put_sync(hba);
out:
@@ -7259,7 +7259,8 @@ static int ufshcd_host_reset_and_restore(struct ufs_hba *hba)
hba->silence_err_logs = false;

/* scale up clocks to max frequency before full reinitialization */
- ufshcd_scale_clks(hba, true);
+ if (ufshcd_is_clkscaling_supported(hba) && hba->clk_scaling.is_enabled)
+ ufshcd_scale_clks(hba, true);

err = ufshcd_hba_enable(hba);

--
2.18.0