2021-01-06 21:44:55

by Jaegeuk Kim

Subject: [PATCH v3 1/2] scsi: ufs: fix livelock of ufshcd_clear_ua_wluns

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 <[email protected]>
---
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 bedb822a40a3..1678cec08b51 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -3996,6 +3996,8 @@ 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;
}
@@ -6003,6 +6005,9 @@ 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);
}

/**
@@ -6940,14 +6945,11 @@ 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);
@@ -8777,6 +8779,7 @@ 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) {
@@ -8887,6 +8890,8 @@ 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

2021-01-07 06:13:10

by Can Guo

Subject: Re: [PATCH v3 1/2] scsi: ufs: fix livelock of ufshcd_clear_ua_wluns

On 2021-01-07 05:41, 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.
>
> Fixes: 1918651f2d7e ("scsi: ufs: Clear UAC for RPMB after ufshcd
> resets")
> Signed-off-by: Jaegeuk Kim <[email protected]>
> ---
> 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 bedb822a40a3..1678cec08b51 100644
> --- a/drivers/scsi/ufs/ufshcd.c
> +++ b/drivers/scsi/ufs/ufshcd.c
> @@ -3996,6 +3996,8 @@ 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);

Can we put it right after ufshcd_scsi_add_wlus() in ufshcd_add_lus()?

Thanks,
Can Guo.

>
> return ret;
> }
> @@ -6003,6 +6005,9 @@ 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);
> }
>
> /**
> @@ -6940,14 +6945,11 @@ 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);
> @@ -8777,6 +8779,7 @@ 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) {
> @@ -8887,6 +8890,8 @@ 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);

2021-01-07 06:59:28

by Jaegeuk Kim

Subject: Re: [PATCH v3 1/2] scsi: ufs: fix livelock of ufshcd_clear_ua_wluns

On 01/07, Can Guo wrote:
> On 2021-01-07 05:41, 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.
> >
> > Fixes: 1918651f2d7e ("scsi: ufs: Clear UAC for RPMB after ufshcd
> > resets")
> > Signed-off-by: Jaegeuk Kim <[email protected]>
> > ---
> > 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 bedb822a40a3..1678cec08b51 100644
> > --- a/drivers/scsi/ufs/ufshcd.c
> > +++ b/drivers/scsi/ufs/ufshcd.c
> > @@ -3996,6 +3996,8 @@ 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);
>
> Can we put it right after ufshcd_scsi_add_wlus() in ufshcd_add_lus()?

May I ask the reason? We'll call it after ufshcd_add_lus() later tho.

>
> Thanks,
> Can Guo.
>
> >
> > return ret;
> > }
> > @@ -6003,6 +6005,9 @@ 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);
> > }
> >
> > /**
> > @@ -6940,14 +6945,11 @@ 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);
> > @@ -8777,6 +8779,7 @@ 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) {
> > @@ -8887,6 +8890,8 @@ 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);

2021-01-07 07:12:58

by Can Guo

Subject: Re: [PATCH v3 1/2] scsi: ufs: fix livelock of ufshcd_clear_ua_wluns

On 2021-01-07 14:57, Jaegeuk Kim wrote:
> On 01/07, Can Guo wrote:
>> On 2021-01-07 05:41, 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.
>> >
>> > Fixes: 1918651f2d7e ("scsi: ufs: Clear UAC for RPMB after ufshcd
>> > resets")
>> > Signed-off-by: Jaegeuk Kim <[email protected]>
>> > ---
>> > 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 bedb822a40a3..1678cec08b51 100644
>> > --- a/drivers/scsi/ufs/ufshcd.c
>> > +++ b/drivers/scsi/ufs/ufshcd.c
>> > @@ -3996,6 +3996,8 @@ 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);
>>
>> Can we put it right after ufshcd_scsi_add_wlus() in ufshcd_add_lus()?
>
> May I ask the reason? We'll call it after ufshcd_add_lus() later tho.
>

I think the code will be more readable - we do all the LU related
stuffs in one func, just nit-picking though. I found this because
I am planning to move the devfreq init codes out of ufshcd_add_lus()
due to it is inappropriate to init devfreq in there by its naming,
but it might be a good place for ufshcd_clear_ua_wluns().

Thanks,
Can Guo.

>>
>> Thanks,
>> Can Guo.
>>
>> >
>> > return ret;
>> > }
>> > @@ -6003,6 +6005,9 @@ 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);
>> > }
>> >
>> > /**
>> > @@ -6940,14 +6945,11 @@ 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);
>> > @@ -8777,6 +8779,7 @@ 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) {
>> > @@ -8887,6 +8890,8 @@ 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);

2021-01-07 07:42:27

by Jaegeuk Kim

Subject: Re: [PATCH v3 1/2] scsi: ufs: fix livelock of ufshcd_clear_ua_wluns

On 01/07, Can Guo wrote:
> On 2021-01-07 14:57, Jaegeuk Kim wrote:
> > On 01/07, Can Guo wrote:
> > > On 2021-01-07 05:41, 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.
> > > >
> > > > Fixes: 1918651f2d7e ("scsi: ufs: Clear UAC for RPMB after ufshcd
> > > > resets")
> > > > Signed-off-by: Jaegeuk Kim <[email protected]>
> > > > ---
> > > > 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 bedb822a40a3..1678cec08b51 100644
> > > > --- a/drivers/scsi/ufs/ufshcd.c
> > > > +++ b/drivers/scsi/ufs/ufshcd.c
> > > > @@ -3996,6 +3996,8 @@ 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);
> > >
> > > Can we put it right after ufshcd_scsi_add_wlus() in ufshcd_add_lus()?
> >
> > May I ask the reason? We'll call it after ufshcd_add_lus() later tho.
> >
>
> I think the code will be more readable - we do all the LU related
> stuffs in one func, just nit-picking though. I found this because
> I am planning to move the devfreq init codes out of ufshcd_add_lus()
> due to it is inappropriate to init devfreq in there by its naming,
> but it might be a good place for ufshcd_clear_ua_wluns().

Ok, that looks good to me. Thanks.

>
> Thanks,
> Can Guo.
>
> > >
> > > Thanks,
> > > Can Guo.
> > >
> > > >
> > > > return ret;
> > > > }
> > > > @@ -6003,6 +6005,9 @@ 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);
> > > > }
> > > >
> > > > /**
> > > > @@ -6940,14 +6945,11 @@ 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);
> > > > @@ -8777,6 +8779,7 @@ 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) {
> > > > @@ -8887,6 +8890,8 @@ 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);