Re: [PATCH v2 3/4] scsi: ufs: Cleanup and refactor clk-scaling feature

From: Can Guo
Date: Fri Dec 18 2020 - 01:17:05 EST


On 2020-12-16 21:16, Stanley Chu wrote:
Manipulate clock scaling related stuff only if the host capability
supports clock scaling feature to avoid redundant code execution.

Signed-off-by: Stanley Chu <stanley.chu@xxxxxxxxxxxx>
---
drivers/scsi/ufs/ufshcd.c | 64 ++++++++++++++++++++-------------------
1 file changed, 33 insertions(+), 31 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 9cc16598136d..ce0528f2e2ed 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -1448,9 +1448,6 @@ static void ufshcd_suspend_clkscaling(struct ufs_hba *hba)
unsigned long flags;
bool suspend = false;

- if (!ufshcd_is_clkscaling_supported(hba))
- return;
-
cancel_work_sync(&hba->clk_scaling.suspend_work);
cancel_work_sync(&hba->clk_scaling.resume_work);

@@ -1470,9 +1467,6 @@ static void ufshcd_resume_clkscaling(struct ufs_hba *hba)
unsigned long flags;
bool resume = false;

- if (!ufshcd_is_clkscaling_supported(hba))
- return;
-
spin_lock_irqsave(hba->host->host_lock, flags);
if (hba->clk_scaling.is_suspended) {
resume = true;
@@ -5642,6 +5636,26 @@ static inline void
ufshcd_schedule_eh_work(struct ufs_hba *hba)
}
}

+static void ufshcd_clk_scaling_allow(struct ufs_hba *hba, bool allow)
+{
+ down_write(&hba->clk_scaling_lock);
+ hba->clk_scaling.is_allowed = allow;
+ up_write(&hba->clk_scaling_lock);
+}
+
+static void ufshcd_clk_scaling_suspend(struct ufs_hba *hba, bool suspend)
+{
+ if (suspend) {
+ if (hba->clk_scaling.is_enabled)
+ ufshcd_suspend_clkscaling(hba);
+ ufshcd_clk_scaling_allow(hba, false);
+ } else {
+ ufshcd_clk_scaling_allow(hba, true);
+ if (hba->clk_scaling.is_enabled)
+ ufshcd_resume_clkscaling(hba);
+ }
+}
+
static void ufshcd_err_handling_prepare(struct ufs_hba *hba)
{
pm_runtime_get_sync(hba->dev);
@@ -5663,23 +5677,20 @@ static void ufshcd_err_handling_prepare(struct
ufs_hba *hba)
ufshcd_vops_resume(hba, UFS_RUNTIME_PM);
} else {
ufshcd_hold(hba, false);
- if (hba->clk_scaling.is_enabled)
+ if (ufshcd_is_clkscaling_supported(hba) &&
+ hba->clk_scaling.is_enabled)
ufshcd_suspend_clkscaling(hba);
}
- down_write(&hba->clk_scaling_lock);
- hba->clk_scaling.is_allowed = false;
- up_write(&hba->clk_scaling_lock);
+ ufshcd_clk_scaling_allow(hba, false);
}

static void ufshcd_err_handling_unprepare(struct ufs_hba *hba)
{
ufshcd_release(hba);

- down_write(&hba->clk_scaling_lock);
- hba->clk_scaling.is_allowed = true;
- up_write(&hba->clk_scaling_lock);
- if (hba->clk_scaling.is_enabled)
- ufshcd_resume_clkscaling(hba);
+ if (ufshcd_is_clkscaling_supported(hba))
+ ufshcd_clk_scaling_suspend(hba, false);
+
pm_runtime_put(hba->dev);
}

@@ -8507,12 +8518,8 @@ static int ufshcd_suspend(struct ufs_hba *hba,
enum ufs_pm_op pm_op)
ufshcd_hold(hba, false);
hba->clk_gating.is_suspended = true;

- if (hba->clk_scaling.is_enabled)
- ufshcd_suspend_clkscaling(hba);
-
- down_write(&hba->clk_scaling_lock);
- hba->clk_scaling.is_allowed = false;
- up_write(&hba->clk_scaling_lock);
+ if (ufshcd_is_clkscaling_supported(hba))
+ ufshcd_clk_scaling_suspend(hba, true);

if (req_dev_pwr_mode == UFS_ACTIVE_PWR_MODE &&
req_link_state == UIC_LINK_ACTIVE_STATE) {
@@ -8618,11 +8625,9 @@ static int ufshcd_suspend(struct ufs_hba *hba,
enum ufs_pm_op pm_op)
if (!ufshcd_set_dev_pwr_mode(hba, UFS_ACTIVE_PWR_MODE))
ufshcd_disable_auto_bkops(hba);
enable_gating:
- down_write(&hba->clk_scaling_lock);
- hba->clk_scaling.is_allowed = true;
- up_write(&hba->clk_scaling_lock);
- if (hba->clk_scaling.is_enabled)
- ufshcd_resume_clkscaling(hba);
+ if (ufshcd_is_clkscaling_supported(hba))
+ ufshcd_clk_scaling_suspend(hba, false);
+
hba->clk_gating.is_suspended = false;
hba->dev_info.b_rpm_dev_flush_capable = false;
ufshcd_release(hba);
@@ -8719,11 +8724,8 @@ static int ufshcd_resume(struct ufs_hba *hba,
enum ufs_pm_op pm_op)

hba->clk_gating.is_suspended = false;

- down_write(&hba->clk_scaling_lock);
- hba->clk_scaling.is_allowed = true;
- up_write(&hba->clk_scaling_lock);
- if (hba->clk_scaling.is_enabled)
- ufshcd_resume_clkscaling(hba);
+ if (ufshcd_is_clkscaling_supported(hba))
+ ufshcd_clk_scaling_suspend(hba, false);

/* Enable Auto-Hibernate if configured */
ufshcd_auto_hibern8_enable(hba);

Thanks for the cleanup

Reviewed-by: Can Guo <cang@xxxxxxxxxxxxxx>