diff mbox series

[v3,5/8] scsi: ufs: Fix ufshcd_hold() caused scheduling while atomic

Message ID 1579759946-5448-6-git-send-email-cang@codeaurora.org (mailing list archive)
State Superseded
Headers show
Series UFS driver general fixes bundle 4 | expand

Commit Message

Can Guo Jan. 23, 2020, 6:12 a.m. UTC
The async version of ufshcd_hold(async == true), which is only called
in queuecommand path as for now, is expected to work in atomic context,
thus it should not sleep or schedule out. When it runs into the condition
that clocks are ON but link is still in hibern8 state, it should bail out
without flushing the clock ungate work.

Signed-off-by: Can Guo <cang@codeaurora.org>
---
 drivers/scsi/ufs/ufshcd.c | 5 +++++
 1 file changed, 5 insertions(+)

Comments

hongwus@codeaurora.org Jan. 23, 2020, 6:50 a.m. UTC | #1
Hi Can,

On 2020-01-23 14:12, Can Guo wrote:
> The async version of ufshcd_hold(async == true), which is only called
> in queuecommand path as for now, is expected to work in atomic context,
> thus it should not sleep or schedule out. When it runs into the 
> condition
> that clocks are ON but link is still in hibern8 state, it should bail 
> out
> without flushing the clock ungate work.
> 
> Signed-off-by: Can Guo <cang@codeaurora.org>
> ---
>  drivers/scsi/ufs/ufshcd.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
> index 4dfd705..c316a07 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -1542,6 +1542,11 @@ int ufshcd_hold(struct ufs_hba *hba, bool async)
>  		 */
>  		if (ufshcd_can_hibern8_during_gating(hba) &&
>  		    ufshcd_is_link_hibern8(hba)) {
> +			if (async) {
> +				rc = -EAGAIN;
> +				hba->clk_gating.active_reqs--;
> +				break;
> +			}
>  			spin_unlock_irqrestore(hba->host->host_lock, flags);
>  			flush_work(&hba->clk_gating.ungate_work);
>  			spin_lock_irqsave(hba->host->host_lock, flags);

It looks good to me.

Reviewed-by: Hongwu Su <hongwus@codeaurora.org>
diff mbox series

Patch

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 4dfd705..c316a07 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -1542,6 +1542,11 @@  int ufshcd_hold(struct ufs_hba *hba, bool async)
 		 */
 		if (ufshcd_can_hibern8_during_gating(hba) &&
 		    ufshcd_is_link_hibern8(hba)) {
+			if (async) {
+				rc = -EAGAIN;
+				hba->clk_gating.active_reqs--;
+				break;
+			}
 			spin_unlock_irqrestore(hba->host->host_lock, flags);
 			flush_work(&hba->clk_gating.ungate_work);
 			spin_lock_irqsave(hba->host->host_lock, flags);