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

[Can Guo <cang@xxxxxxxxxxxxxx>]

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>