lkml.org 
[lkml]   [2023]   [Jan]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH] scsi: ufs: core: fix devfreq deadlocks
From
On 12/22/22 02:21, Johan Hovold wrote:
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index bda61be5f035..5c3821b2fcf8 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -1234,12 +1234,14 @@ static int ufshcd_clock_scaling_prepare(struct ufs_hba *hba)
> * clock scaling is in progress
> */
> ufshcd_scsi_block_requests(hba);
> + mutex_lock(&hba->wb_mutex);
> down_write(&hba->clk_scaling_lock);
>
> if (!hba->clk_scaling.is_allowed ||
> ufshcd_wait_for_doorbell_clr(hba, DOORBELL_CLR_TOUT_US)) {
> ret = -EBUSY;
> up_write(&hba->clk_scaling_lock);
> + mutex_unlock(&hba->wb_mutex);
> ufshcd_scsi_unblock_requests(hba);
> goto out;
> }
> @@ -1251,12 +1253,16 @@ static int ufshcd_clock_scaling_prepare(struct ufs_hba *hba)
> return ret;
> }

Please add an __acquires(&hba->wb_mutex) annotation for sparse.

> -static void ufshcd_clock_scaling_unprepare(struct ufs_hba *hba, bool writelock)
> +static void ufshcd_clock_scaling_unprepare(struct ufs_hba *hba, bool scale_up)
> {
> - if (writelock)
> - up_write(&hba->clk_scaling_lock);
> - else
> - up_read(&hba->clk_scaling_lock);
> + up_write(&hba->clk_scaling_lock);
> +
> + /* Enable Write Booster if we have scaled up else disable it */
> + if (ufshcd_enable_wb_if_scaling_up(hba))
> + ufshcd_wb_toggle(hba, scale_up);
> +
> + mutex_unlock(&hba->wb_mutex);
> +
> ufshcd_scsi_unblock_requests(hba);
> ufshcd_release(hba);
> }

Please add a __releases(&hba->wb_mutex) annotation for sparse.

> @@ -1273,7 +1279,6 @@ static void ufshcd_clock_scaling_unprepare(struct ufs_hba *hba, bool writelock)
> static int ufshcd_devfreq_scale(struct ufs_hba *hba, bool scale_up)
> {
> int ret = 0;
> - bool is_writelock = true;
>
> ret = ufshcd_clock_scaling_prepare(hba);
> if (ret)
> @@ -1302,15 +1307,8 @@ static int ufshcd_devfreq_scale(struct ufs_hba *hba, bool scale_up)
> }
> }
>
> - /* Enable Write Booster if we have scaled up else disable it */
> - if (ufshcd_enable_wb_if_scaling_up(hba)) {
> - downgrade_write(&hba->clk_scaling_lock);
> - is_writelock = false;
> - ufshcd_wb_toggle(hba, scale_up);
> - }
> -
> out_unprepare:
> - ufshcd_clock_scaling_unprepare(hba, is_writelock);
> + ufshcd_clock_scaling_unprepare(hba, scale_up);
> return ret;
> }

This patch moves the ufshcd_wb_toggle() from before the out_unprepare
label to after the out_unprepare label (into
ufshcd_clock_scaling_unprepare()). Does this change perhaps introduce a
new call to ufshcd_wb_toggle() in error paths?

Thanks,

Bart.

\
 
 \ /
  Last update: 2023-03-26 23:29    [W:0.124 / U:0.876 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site