diff mbox series

scsi: ufs: fix livelock of ufshcd_clear_ua_wluns

Message ID 20201218033131.2624065-1-jaegeuk@kernel.org
State Superseded
Headers show
Series scsi: ufs: fix livelock of ufshcd_clear_ua_wluns | expand

Commit Message

Jaegeuk Kim Dec. 18, 2020, 3:31 a.m. UTC
When gate_work/ungate_work gets an error during hibern8_enter or exit,
 ufshcd_err_handler()
   ufshcd_scsi_block_requests()
   ufshcd_reset_and_restore()
     ufshcd_clear_ua_wluns() -> stuck
   ufshcd_scsi_unblock_requests()

In order to avoid it, ufshcd_clear_ua_wluns() can be called per recovery flows
such as suspend/resume, link_recovery, and error_handler.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 drivers/scsi/ufs/ufshcd.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

Comments

Avri Altman Dec. 20, 2020, 10:02 p.m. UTC | #1
Hi J,
 
> 

> When gate_work/ungate_work gets an error during hibern8_enter or exit,

>  ufshcd_err_handler()

>    ufshcd_scsi_block_requests()

>    ufshcd_reset_and_restore()

>      ufshcd_clear_ua_wluns() -> stuck

>    ufshcd_scsi_unblock_requests()

> 

> In order to avoid it, ufshcd_clear_ua_wluns() can be called per recovery

> flows

> such as suspend/resume, link_recovery, and error_handler.

Not sure that suspend/resume are UAC events?
 
Also the 'fixes' tag is missing.

Thanks,
Avri
Can Guo Dec. 21, 2020, 4:25 a.m. UTC | #2
On 2020-12-18 11:31, Jaegeuk Kim wrote:
> When gate_work/ungate_work gets an error during hibern8_enter or exit,

>  ufshcd_err_handler()

>    ufshcd_scsi_block_requests()

>    ufshcd_reset_and_restore()

>      ufshcd_clear_ua_wluns() -> stuck

>    ufshcd_scsi_unblock_requests()

> 

> In order to avoid it, ufshcd_clear_ua_wluns() can be called per 

> recovery flows

> such as suspend/resume, link_recovery, and error_handler.

> 

> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

> ---

>  drivers/scsi/ufs/ufshcd.c | 14 +++++++++-----

>  1 file changed, 9 insertions(+), 5 deletions(-)

> 

> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c

> index e221add25a7e..e711def829cd 100644

> --- a/drivers/scsi/ufs/ufshcd.c

> +++ b/drivers/scsi/ufs/ufshcd.c

> @@ -3963,6 +3963,8 @@ int ufshcd_link_recovery(struct ufs_hba *hba)

>  	if (ret)

>  		dev_err(hba->dev, "%s: link recovery failed, err %d",

>  			__func__, ret);

> +	else

> +		ufshcd_clear_ua_wluns(hba);

> 

>  	return ret;

>  }

> @@ -5968,6 +5970,8 @@ static void ufshcd_err_handler(struct work_struct 

> *work)

>  	ufshcd_scsi_unblock_requests(hba);

>  	ufshcd_err_handling_unprepare(hba);

>  	up(&hba->eh_sem);

> +


Maybe add a check like if (!err && needs_reset) as error handler
also handles non-fatal errors which do not require a full reset
and restore?

> +	ufshcd_clear_ua_wluns(hba);

>  }

> 

>  /**

> @@ -6908,14 +6912,11 @@ static int

> ufshcd_host_reset_and_restore(struct ufs_hba *hba)

>  	ufshcd_set_clk_freq(hba, true);

> 

>  	err = ufshcd_hba_enable(hba);

> -	if (err)

> -		goto out;

> 

>  	/* Establish the link again and restore the device */

> -	err = ufshcd_probe_hba(hba, false);

>  	if (!err)

> -		ufshcd_clear_ua_wluns(hba);

> -out:

> +		err = ufshcd_probe_hba(hba, false);

> +

>  	if (err)

>  		dev_err(hba->dev, "%s: Host init failed %d\n", __func__, err);

>  	ufshcd_update_evt_hist(hba, UFS_EVT_HOST_RESET, (u32)err);

> @@ -8745,6 +8746,7 @@ static int ufshcd_suspend(struct ufs_hba *hba,

> enum ufs_pm_op pm_op)

>  		ufshcd_resume_clkscaling(hba);

>  	hba->clk_gating.is_suspended = false;

>  	hba->dev_info.b_rpm_dev_flush_capable = false;

> +	ufshcd_clear_ua_wluns(hba);

>  	ufshcd_release(hba);

>  out:

>  	if (hba->dev_info.b_rpm_dev_flush_capable) {

> @@ -8855,6 +8857,8 @@ static int ufshcd_resume(struct ufs_hba *hba,

> enum ufs_pm_op pm_op)

>  		cancel_delayed_work(&hba->rpm_dev_flush_recheck_work);

>  	}

> 

> +	ufshcd_clear_ua_wluns(hba);

> +

>  	/* Schedule clock gating in case of no access to UFS device yet */

>  	ufshcd_release(hba);
Jaegeuk Kim Dec. 21, 2020, 3:14 p.m. UTC | #3
On 12/21, Can Guo wrote:
> On 2020-12-18 11:31, Jaegeuk Kim wrote:

> > When gate_work/ungate_work gets an error during hibern8_enter or exit,

> >  ufshcd_err_handler()

> >    ufshcd_scsi_block_requests()

> >    ufshcd_reset_and_restore()

> >      ufshcd_clear_ua_wluns() -> stuck

> >    ufshcd_scsi_unblock_requests()

> > 

> > In order to avoid it, ufshcd_clear_ua_wluns() can be called per recovery

> > flows

> > such as suspend/resume, link_recovery, and error_handler.

> > 

> > Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

> > ---

> >  drivers/scsi/ufs/ufshcd.c | 14 +++++++++-----

> >  1 file changed, 9 insertions(+), 5 deletions(-)

> > 

> > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c

> > index e221add25a7e..e711def829cd 100644

> > --- a/drivers/scsi/ufs/ufshcd.c

> > +++ b/drivers/scsi/ufs/ufshcd.c

> > @@ -3963,6 +3963,8 @@ int ufshcd_link_recovery(struct ufs_hba *hba)

> >  	if (ret)

> >  		dev_err(hba->dev, "%s: link recovery failed, err %d",

> >  			__func__, ret);

> > +	else

> > +		ufshcd_clear_ua_wluns(hba);

> > 

> >  	return ret;

> >  }

> > @@ -5968,6 +5970,8 @@ static void ufshcd_err_handler(struct work_struct

> > *work)

> >  	ufshcd_scsi_unblock_requests(hba);

> >  	ufshcd_err_handling_unprepare(hba);

> >  	up(&hba->eh_sem);

> > +

> 

> Maybe add a check like if (!err && needs_reset) as error handler

> also handles non-fatal errors which do not require a full reset

> and restore?


I see. Let me add it in v2.

> 

> > +	ufshcd_clear_ua_wluns(hba);

> >  }

> > 

> >  /**

> > @@ -6908,14 +6912,11 @@ static int

> > ufshcd_host_reset_and_restore(struct ufs_hba *hba)

> >  	ufshcd_set_clk_freq(hba, true);

> > 

> >  	err = ufshcd_hba_enable(hba);

> > -	if (err)

> > -		goto out;

> > 

> >  	/* Establish the link again and restore the device */

> > -	err = ufshcd_probe_hba(hba, false);

> >  	if (!err)

> > -		ufshcd_clear_ua_wluns(hba);

> > -out:

> > +		err = ufshcd_probe_hba(hba, false);

> > +

> >  	if (err)

> >  		dev_err(hba->dev, "%s: Host init failed %d\n", __func__, err);

> >  	ufshcd_update_evt_hist(hba, UFS_EVT_HOST_RESET, (u32)err);

> > @@ -8745,6 +8746,7 @@ static int ufshcd_suspend(struct ufs_hba *hba,

> > enum ufs_pm_op pm_op)

> >  		ufshcd_resume_clkscaling(hba);

> >  	hba->clk_gating.is_suspended = false;

> >  	hba->dev_info.b_rpm_dev_flush_capable = false;

> > +	ufshcd_clear_ua_wluns(hba);

> >  	ufshcd_release(hba);

> >  out:

> >  	if (hba->dev_info.b_rpm_dev_flush_capable) {

> > @@ -8855,6 +8857,8 @@ static int ufshcd_resume(struct ufs_hba *hba,

> > enum ufs_pm_op pm_op)

> >  		cancel_delayed_work(&hba->rpm_dev_flush_recheck_work);

> >  	}

> > 

> > +	ufshcd_clear_ua_wluns(hba);

> > +

> >  	/* Schedule clock gating in case of no access to UFS device yet */

> >  	ufshcd_release(hba);
Jaegeuk Kim Dec. 21, 2020, 3:23 p.m. UTC | #4
Hi,

On 12/20, Avri Altman wrote:
> Hi J,

>  

> > 

> > When gate_work/ungate_work gets an error during hibern8_enter or exit,

> >  ufshcd_err_handler()

> >    ufshcd_scsi_block_requests()

> >    ufshcd_reset_and_restore()

> >      ufshcd_clear_ua_wluns() -> stuck

> >    ufshcd_scsi_unblock_requests()

> > 

> > In order to avoid it, ufshcd_clear_ua_wluns() can be called per recovery

> > flows

> > such as suspend/resume, link_recovery, and error_handler.

> Not sure that suspend/resume are UAC events?


Could you elaborate a bit? The goal is to clear UAC after UFS reset happens.

>  

> Also the 'fixes' tag is missing.


Added. Thanks,

> 

> Thanks,

> Avri
Jaegeuk Kim Dec. 21, 2020, 3:26 p.m. UTC | #5
When gate_work/ungate_work gets an error during hibern8_enter or exit,
 ufshcd_err_handler()
   ufshcd_scsi_block_requests()
   ufshcd_reset_and_restore()
     ufshcd_clear_ua_wluns() -> stuck
   ufshcd_scsi_unblock_requests()

In order to avoid it, ufshcd_clear_ua_wluns() can be called per recovery flows
such as suspend/resume, link_recovery, and error_handler.

Fixes: 1918651f2d7e ("scsi: ufs: Clear UAC for RPMB after ufshcd resets")
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

---

 Change log from v1:
  - add condition check to call
  - add Fixes tag

 drivers/scsi/ufs/ufshcd.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index e221add25a7e..29a62552f6f1 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -3963,6 +3963,8 @@ int ufshcd_link_recovery(struct ufs_hba *hba)
 	if (ret)
 		dev_err(hba->dev, "%s: link recovery failed, err %d",
 			__func__, ret);
+	else
+		ufshcd_clear_ua_wluns(hba);
 
 	return ret;
 }
@@ -5968,6 +5970,9 @@ static void ufshcd_err_handler(struct work_struct *work)
 	ufshcd_scsi_unblock_requests(hba);
 	ufshcd_err_handling_unprepare(hba);
 	up(&hba->eh_sem);
+
+	if (!err && needs_reset)
+		ufshcd_clear_ua_wluns(hba);
 }
 
 /**
@@ -6908,14 +6913,11 @@ static int ufshcd_host_reset_and_restore(struct ufs_hba *hba)
 	ufshcd_set_clk_freq(hba, true);
 
 	err = ufshcd_hba_enable(hba);
-	if (err)
-		goto out;
 
 	/* Establish the link again and restore the device */
-	err = ufshcd_probe_hba(hba, false);
 	if (!err)
-		ufshcd_clear_ua_wluns(hba);
-out:
+		err = ufshcd_probe_hba(hba, false);
+
 	if (err)
 		dev_err(hba->dev, "%s: Host init failed %d\n", __func__, err);
 	ufshcd_update_evt_hist(hba, UFS_EVT_HOST_RESET, (u32)err);
@@ -8745,6 +8747,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 		ufshcd_resume_clkscaling(hba);
 	hba->clk_gating.is_suspended = false;
 	hba->dev_info.b_rpm_dev_flush_capable = false;
+	ufshcd_clear_ua_wluns(hba);
 	ufshcd_release(hba);
 out:
 	if (hba->dev_info.b_rpm_dev_flush_capable) {
@@ -8855,6 +8858,8 @@ static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 		cancel_delayed_work(&hba->rpm_dev_flush_recheck_work);
 	}
 
+	ufshcd_clear_ua_wluns(hba);
+
 	/* Schedule clock gating in case of no access to UFS device yet */
 	ufshcd_release(hba);
 
-- 
2.29.2.729.g45daf8777d-goog
Avri Altman Dec. 21, 2020, 5 p.m. UTC | #6
> > > When gate_work/ungate_work gets an error during hibern8_enter or

> exit,

> > >  ufshcd_err_handler()

> > >    ufshcd_scsi_block_requests()

> > >    ufshcd_reset_and_restore()

> > >      ufshcd_clear_ua_wluns() -> stuck

> > >    ufshcd_scsi_unblock_requests()

> > >

> > > In order to avoid it, ufshcd_clear_ua_wluns() can be called per recovery

> > > flows

> > > such as suspend/resume, link_recovery, and error_handler.

> > Not sure that suspend/resume are UAC events?

> 

> Could you elaborate a bit? The goal is to clear UAC after UFS reset happens.

So why calling it on every suspend and resume?

> 

> >

> > Also the 'fixes' tag is missing.

> 

> Added. Thanks,

> 

> >

> > Thanks,

> > Avri
Jaegeuk Kim Dec. 21, 2020, 5:19 p.m. UTC | #7
On 12/21, Avri Altman wrote:
> > > > When gate_work/ungate_work gets an error during hibern8_enter or

> > exit,

> > > >  ufshcd_err_handler()

> > > >    ufshcd_scsi_block_requests()

> > > >    ufshcd_reset_and_restore()

> > > >      ufshcd_clear_ua_wluns() -> stuck

> > > >    ufshcd_scsi_unblock_requests()

> > > >

> > > > In order to avoid it, ufshcd_clear_ua_wluns() can be called per recovery

> > > > flows

> > > > such as suspend/resume, link_recovery, and error_handler.

> > > Not sure that suspend/resume are UAC events?

> > 

> > Could you elaborate a bit? The goal is to clear UAC after UFS reset happens.

> So why calling it on every suspend and resume?


1. If UAC was cleared, there's no impact. 
2. ufshcd_link_recovery() can reset UFS directly by ufs_mtk_resume().
3. ufshcd_suspend can call ufshcd_host_reset_and_restore() as well.

> 

> > 

> > >

> > > Also the 'fixes' tag is missing.

> > 

> > Added. Thanks,

> > 

> > >

> > > Thanks,

> > > Avri
Avri Altman Dec. 21, 2020, 6:05 p.m. UTC | #8
> 

> 

> On 12/21, Avri Altman wrote:

> > > > > When gate_work/ungate_work gets an error during hibern8_enter or

> > > exit,

> > > > >  ufshcd_err_handler()

> > > > >    ufshcd_scsi_block_requests()

> > > > >    ufshcd_reset_and_restore()

> > > > >      ufshcd_clear_ua_wluns() -> stuck

> > > > >    ufshcd_scsi_unblock_requests()

> > > > >

> > > > > In order to avoid it, ufshcd_clear_ua_wluns() can be called per

> recovery

> > > > > flows

> > > > > such as suspend/resume, link_recovery, and error_handler.

> > > > Not sure that suspend/resume are UAC events?

> > >

> > > Could you elaborate a bit? The goal is to clear UAC after UFS reset

> happens.

> > So why calling it on every suspend and resume?

> 

> 1. If UAC was cleared, there's no impact.

But the command is still sent.

> 2. ufshcd_link_recovery() can reset UFS directly by ufs_mtk_resume().

> 3. ufshcd_suspend can call ufshcd_host_reset_and_restore() as well.

Seems excessive IMO.
Why not selectively send when indeed required, e.g. on reset?
Jaegeuk Kim Dec. 21, 2020, 7:35 p.m. UTC | #9
On 12/21, Avri Altman wrote:
> > 

> > 

> > On 12/21, Avri Altman wrote:

> > > > > > When gate_work/ungate_work gets an error during hibern8_enter or

> > > > exit,

> > > > > >  ufshcd_err_handler()

> > > > > >    ufshcd_scsi_block_requests()

> > > > > >    ufshcd_reset_and_restore()

> > > > > >      ufshcd_clear_ua_wluns() -> stuck

> > > > > >    ufshcd_scsi_unblock_requests()

> > > > > >

> > > > > > In order to avoid it, ufshcd_clear_ua_wluns() can be called per

> > recovery

> > > > > > flows

> > > > > > such as suspend/resume, link_recovery, and error_handler.

> > > > > Not sure that suspend/resume are UAC events?

> > > >

> > > > Could you elaborate a bit? The goal is to clear UAC after UFS reset

> > happens.

> > > So why calling it on every suspend and resume?

> > 

> > 1. If UAC was cleared, there's no impact.

> But the command is still sent.


No, ufshcd_clear_ua_wluns() will return by hba->wlun_dev_clr_ua.

> 

> > 2. ufshcd_link_recovery() can reset UFS directly by ufs_mtk_resume().

> > 3. ufshcd_suspend can call ufshcd_host_reset_and_restore() as well.

> Seems excessive IMO.

> Why not selectively send when indeed required, e.g. on reset?


I think hba->wlun_dev_clr_ua is the indicator whether there was a reset or not.
Avri Altman Dec. 21, 2020, 8:13 p.m. UTC | #10
> > > > > > > In order to avoid it, ufshcd_clear_ua_wluns() can be called per

> > > recovery

> > > > > > > flows

> > > > > > > such as suspend/resume, link_recovery, and error_handler.

> > > > > > Not sure that suspend/resume are UAC events?

> > > > >

> > > > > Could you elaborate a bit? The goal is to clear UAC after UFS reset

> > > happens.

> > > > So why calling it on every suspend and resume?

> > >

> > > 1. If UAC was cleared, there's no impact.

> > But the command is still sent.

> 

> No, ufshcd_clear_ua_wluns() will return by hba->wlun_dev_clr_ua.

> 

> >

> > > 2. ufshcd_link_recovery() can reset UFS directly by ufs_mtk_resume().

> > > 3. ufshcd_suspend can call ufshcd_host_reset_and_restore() as well.

> > Seems excessive IMO.

> > Why not selectively send when indeed required, e.g. on reset?

> 

> I think hba->wlun_dev_clr_ua is the indicator whether there was a reset or

> not.

Ahha - I missed that.  Thanks for clarifying it.
OK Then.

Thanks,
Avri
Martin K. Petersen Jan. 6, 2021, 3:45 a.m. UTC | #11
Jaegeuk,

> When gate_work/ungate_work gets an error during hibern8_enter or exit,

>  ufshcd_err_handler()

>    ufshcd_scsi_block_requests()

>    ufshcd_reset_and_restore()

>      ufshcd_clear_ua_wluns() -> stuck

>    ufshcd_scsi_unblock_requests()

>

> In order to avoid it, ufshcd_clear_ua_wluns() can be called per recovery flows

> such as suspend/resume, link_recovery, and error_handler.

>

> Fixes: 1918651f2d7e ("scsi: ufs: Clear UAC for RPMB after ufshcd resets")

> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>


Please resubmit instead of replying to an existing patch. Both b4 and
patchwork get confused.

Thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering
Jaegeuk Kim Jan. 6, 2021, 4:28 a.m. UTC | #12
On 01/05, Martin K. Petersen wrote:
> 

> Jaegeuk,

> 

> > When gate_work/ungate_work gets an error during hibern8_enter or exit,

> >  ufshcd_err_handler()

> >    ufshcd_scsi_block_requests()

> >    ufshcd_reset_and_restore()

> >      ufshcd_clear_ua_wluns() -> stuck

> >    ufshcd_scsi_unblock_requests()

> >

> > In order to avoid it, ufshcd_clear_ua_wluns() can be called per recovery flows

> > such as suspend/resume, link_recovery, and error_handler.

> >

> > Fixes: 1918651f2d7e ("scsi: ufs: Clear UAC for RPMB after ufshcd resets")

> > Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

> 

> Please resubmit instead of replying to an existing patch. Both b4 and

> patchwork get confused.


Ok, I posted a new one. Thanks,

> 

> Thanks!

> 

> -- 

> Martin K. Petersen	Oracle Linux Engineering
diff mbox series

Patch

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index e221add25a7e..e711def829cd 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -3963,6 +3963,8 @@  int ufshcd_link_recovery(struct ufs_hba *hba)
 	if (ret)
 		dev_err(hba->dev, "%s: link recovery failed, err %d",
 			__func__, ret);
+	else
+		ufshcd_clear_ua_wluns(hba);
 
 	return ret;
 }
@@ -5968,6 +5970,8 @@  static void ufshcd_err_handler(struct work_struct *work)
 	ufshcd_scsi_unblock_requests(hba);
 	ufshcd_err_handling_unprepare(hba);
 	up(&hba->eh_sem);
+
+	ufshcd_clear_ua_wluns(hba);
 }
 
 /**
@@ -6908,14 +6912,11 @@  static int ufshcd_host_reset_and_restore(struct ufs_hba *hba)
 	ufshcd_set_clk_freq(hba, true);
 
 	err = ufshcd_hba_enable(hba);
-	if (err)
-		goto out;
 
 	/* Establish the link again and restore the device */
-	err = ufshcd_probe_hba(hba, false);
 	if (!err)
-		ufshcd_clear_ua_wluns(hba);
-out:
+		err = ufshcd_probe_hba(hba, false);
+
 	if (err)
 		dev_err(hba->dev, "%s: Host init failed %d\n", __func__, err);
 	ufshcd_update_evt_hist(hba, UFS_EVT_HOST_RESET, (u32)err);
@@ -8745,6 +8746,7 @@  static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 		ufshcd_resume_clkscaling(hba);
 	hba->clk_gating.is_suspended = false;
 	hba->dev_info.b_rpm_dev_flush_capable = false;
+	ufshcd_clear_ua_wluns(hba);
 	ufshcd_release(hba);
 out:
 	if (hba->dev_info.b_rpm_dev_flush_capable) {
@@ -8855,6 +8857,8 @@  static int ufshcd_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 		cancel_delayed_work(&hba->rpm_dev_flush_recheck_work);
 	}
 
+	ufshcd_clear_ua_wluns(hba);
+
 	/* Schedule clock gating in case of no access to UFS device yet */
 	ufshcd_release(hba);