[PATCH 15/24] drm/amd/display: Fix deadlock when flushing irq

[Andrey Grodzovsky]

You guys just need to revert it on dal-dev branch and don't promote to 
amd-staging-drm-next.


So NAK for the change.



Thanks,

Andrey


On 01/22/2018 09:38 AM, Lipski, Mikita wrote:
>
> Hi Andrey,
>
>
> I've checked to revert this change and use Alex's change on switching 
> irq destruction sequence and it worked no problem.
> You can reject this change if Alex's change is pulled in.
>
>
> Thanks,
>
> Nick
>
> ------------------------------------------------------------------------
> *From:* Grodzovsky, Andrey
> *Sent:* Friday, January 19, 2018 1:33:51 PM
> *To:* Wentland, Harry; amd-gfx at lists.freedesktop.org
> *Cc:* Lipski, Mikita
> *Subject:* Re: [PATCH 15/24] drm/amd/display: Fix deadlock when 
> flushing irq
> What this spin lock is protecting here ? Seems to me it's just a read of
> an array element which is always there.
>
> Regarding subsequent remove_timer_handler and timer queue destruction it
> seems to me to be obsolete code, I don't think DAL is still using the
> timer queue,
>
> so seems to me everything related to it should be removed.
>
> Thanks,
>
> Andrey
>
>
> On 01/18/2018 04:03 PM, Harry Wentland wrote:
> > From: Mikita Lipski <mikita.lipski at amd.com>
> >
> > Lock irq table when reading a work in queue,
> > unlock to flush the work, lock again till all tasks
> > are cleared
> >
> > Signed-off-by: Mikita Lipski <mikita.lipski at amd.com>
> > Reviewed-by: Harry Wentland <Harry.Wentland at amd.com>
> > ---
> > drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_irq.c | 5 +++--
> >   1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_irq.c 
> b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_irq.c
> > index 1874b6cee6af..fb60c91a1bfe 100644
> > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_irq.c
> > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_irq.c
> > @@ -400,14 +400,15 @@ void amdgpu_dm_irq_fini(struct amdgpu_device 
> *adev)
> >   {
> >        int src;
> >        struct irq_list_head *lh;
> > +     unsigned long irq_table_flags;
> >        DRM_DEBUG_KMS("DM_IRQ: releasing resources.\n");
> > -
> >        for (src = 0; src < DAL_IRQ_SOURCES_NUMBER; src++) {
> > -
> > +             DM_IRQ_TABLE_LOCK(adev, irq_table_flags);
> >                /* The handler was removed from the table,
> >                 * it means it is safe to flush all the 'work'
> >                 * (because no code can schedule a new one). */
> >                lh = &adev->dm.irq_handler_list_low_tab[src];
> > +             DM_IRQ_TABLE_UNLOCK(adev, irq_table_flags);
> >                flush_work(&lh->work);
> >        }
> >
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/amd-gfx/attachments/20180122/1f9ee016/attachment-0001.html>