Re: [PATCH 1/2] scsi: ufs: Protect some contexts from unexpected clock scaling
From: Bean Huo
Date: Thu Dec 10 2020 - 12:36:06 EST
Hi Can
On Wed, 2020-12-09 at 05:35 -0800, Can Guo wrote:
>
>
> @@ -1160,6 +1166,7 @@ static void
> ufshcd_clock_scaling_unprepare(struct ufs_hba *hba)
> {
> up_write(&hba->clk_scaling_lock);
> ufshcd_scsi_unblock_requests(hba);
> + ufshcd_release(hba);
> }
>
> /**
> @@ -1175,12 +1182,9 @@ static int ufshcd_devfreq_scale(struct ufs_hba
> *hba, bool scale_up)
> {
> int ret = 0;
>
> - /* let's not get into low power until clock scaling is
> completed */
> - ufshcd_hold(hba, false);
> -
> ret = ufshcd_clock_scaling_prepare(hba);
> if (ret)
> - goto out;
> + return ret;
>
> /* scale down the gear before scaling down clocks */
> if (!scale_up) {
> @@ -1212,8 +1216,6 @@ static int ufshcd_devfreq_scale(struct ufs_hba
> *hba, bool scale_up)
>
> out_unprepare:
> ufshcd_clock_scaling_unprepare(hba);
> -out:
> - ufshcd_release(hba);
> return ret;
> }
I didn't understand why moving ufshcd_hold/ufshcd_release into
ufshcd_clock_scaling_prepare()/ufshcd_clock_scaling_unprepare().
>
> @@ -1294,15 +1296,8 @@ static int ufshcd_devfreq_target(struct device
> *dev,
> }
> spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
>
> - pm_runtime_get_noresume(hba->dev);
> - if (!pm_runtime_active(hba->dev)) {
> - pm_runtime_put_noidle(hba->dev);
> - ret = -EAGAIN;
> - goto out;
> - }
> start = ktime_get();
> ret = ufshcd_devfreq_scale(hba, scale_up);
> - pm_runtime_put(hba->dev);
>
which branch are you working on? I didn't see this part codes in the
branch 5.11/scsi-queue and 5.11/scsi-staging.
Bean