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

[Can Guo]

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....@mediatek.com>
---
 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 <c...@codeaurora.org>