On 2020-10-27 11:33, Jaegeuk Kim wrote:
On 10/27, Can Guo wrote:
On 2020-10-27 03:51, Jaegeuk Kim wrote:
> From: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
>
> When giving a stress test which enables/disables clkgating, we hit
> device
> timeout sometimes. This patch avoids subtle racy condition to address
> it.
>
> Note that, this requires a patch to address the device stuck by
> REQ_CLKS_OFF in
> __ufshcd_release().
>
> The fix is "scsi: ufs: avoid to call REQ_CLKS_OFF to CLKS_OFF".
Why don't you just squash the fix into this one?
I'm seeing this patch just revealed that problem.
That scenario (back to back calling of ufshcd_release()) only happens
when you stress the clkgate_enable sysfs node, so let's keep the fix
as one to make things simple. What do you think?
Thanks,
Can Guo.
Thanks,
Can Guo.
>
> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> ---
> drivers/scsi/ufs/ufshcd.c | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index cc8d5f0c3fdc..6c9269bffcbd 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -1808,19 +1808,19 @@ static ssize_t
> ufshcd_clkgate_enable_store(struct device *dev,
> return -EINVAL;
>
> value = !!value;
> +
> + spin_lock_irqsave(hba->host->host_lock, flags);
> if (value == hba->clk_gating.is_enabled)
> goto out;
>
> - if (value) {
> - ufshcd_release(hba);
> - } else {
> - spin_lock_irqsave(hba->host->host_lock, flags);
> + if (value)
> + __ufshcd_release(hba);
> + else
> hba->clk_gating.active_reqs++;
> - spin_unlock_irqrestore(hba->host->host_lock, flags);
> - }
>
> hba->clk_gating.is_enabled = value;
> out:
> + spin_unlock_irqrestore(hba->host->host_lock, flags);
> return count;
> }
