Re: [PATCH] drm/tilcdc: send vblank event when disabling crtc

[quanyang.wang]

Hi Jyri,

On 2/9/21 3:58 PM, Jyri Sarha wrote:
> On 2021-02-09 5:09, quanyang.wang wrote:
> > Ping.
>
> Could you resend the original patch (I have not received it) so I can 
> easily test and merge it?

OK, I will resend it.

Thanks,

Quanyang

> I'll find some time to do it soon.
>
> Best regards,
> Jyri
>
> > On 1/29/21 3:58 PM, Tomi Valkeinen wrote:
> > > Dropped the @ti.com addresses and added the new ones.
> > >
> > >   Tomi
> > >
> > > On 29/01/2021 07:58, quanyang.wang@xxxxxxxxxxxxx wrote:
> > > > From: Quanyang Wang <quanyang.wang@xxxxxxxxxxxxx>
> > > >
> > > > When run xrandr to change resolution on Beaglebone Black board, it 
> > > > will
> > > > print the error information:
> > > >
> > > > root@beaglebone:~# xrandr -display :0 --output HDMI-1 --mode 720x400
> > > > [drm:drm_crtc_commit_wait] *ERROR* flip_done timed out
> > > > [drm:drm_atomic_helper_wait_for_dependencies] *ERROR* 
> > > > [CRTC:32:tilcdc crtc] commit wait timed out
> > > > [drm:drm_crtc_commit_wait] *ERROR* flip_done timed out
> > > > [drm:drm_atomic_helper_wait_for_dependencies] *ERROR* 
> > > > [CONNECTOR:34:HDMI-A-1] commit wait timed out
> > > > [drm:drm_crtc_commit_wait] *ERROR* flip_done timed out
> > > > [drm:drm_atomic_helper_wait_for_dependencies] *ERROR* 
> > > > [PLANE:31:plane-0] commit wait timed out
> > > > tilcdc 4830e000.lcdc: already pending page flip!
> > > >
> > > > This is because there is operation sequence as below:
> > > >
> > > > drm_atomic_connector_commit_dpms(mode is DRM_MODE_DPMS_OFF):
> > > >      ...
> > > >      drm_atomic_helper_setup_commit <- 
> > > > init_completion(commit_A->flip_done)
> > > >      drm_atomic_helper_commit_tail
> > > >          tilcdc_crtc_atomic_disable
> > > >          tilcdc_plane_atomic_update <- drm_crtc_send_vblank_event 
> > > > in tilcdc_crtc_irq
> > > >                                        is skipped since 
> > > > tilcdc_crtc->enabled is 0
> > > >          tilcdc_crtc_atomic_flush   <- drm_crtc_send_vblank_event 
> > > > is skipped since
> > > > crtc->state->event is set to be NULL in
> > > > tilcdc_plane_atomic_update
> > > > drm_mode_setcrtc:
> > > >      ...
> > > >      drm_atomic_helper_setup_commit <- 
> > > > init_completion(commit_B->flip_done)
> > > >      drm_atomic_helper_wait_for_dependencies
> > > >          drm_crtc_commit_wait   <- wait for commit_A->flip_done 
> > > > completing
> > > >
> > > > Just as shown above, the steps which could complete 
> > > > commit_A->flip_done
> > > > are all skipped and commit_A->flip_done will never be completed. 
> > > > This will
> > > > result a time-out ERROR when drm_crtc_commit_wait check the 
> > > > commit_A->flip_done.
> > > > So add drm_crtc_send_vblank_event in tilcdc_crtc_atomic_disable to
> > > > complete commit_A->flip_done.
> > > >
> > > > Fixes: cb345decb4d2 ("drm/tilcdc: Use standard 
> > > > drm_atomic_helper_commit")
> > > > Signed-off-by: Quanyang Wang <quanyang.wang@xxxxxxxxxxxxx>
> > > > ---
> > > >   drivers/gpu/drm/tilcdc/tilcdc_crtc.c | 9 +++++++++
> > > >   1 file changed, 9 insertions(+)
> > > >
> > > > diff --git a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c 
> > > > b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
> > > > index 30213708fc99..d99afd19ca08 100644
> > > > --- a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
> > > > +++ b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c
> > > > @@ -515,6 +515,15 @@ static void tilcdc_crtc_off(struct drm_crtc 
> > > > *crtc, bool shutdown)
> > > >         drm_crtc_vblank_off(crtc);
> > > >   +    spin_lock_irq(&crtc->dev->event_lock);
> > > > +
> > > > +    if (crtc->state->event) {
> > > > +        drm_crtc_send_vblank_event(crtc, crtc->state->event);
> > > > +        crtc->state->event = NULL;
> > > > +    }
> > > > +
> > > > +    spin_unlock_irq(&crtc->dev->event_lock);
> > > > +
> > > >       tilcdc_crtc_disable_irqs(dev);
> > > >         pm_runtime_put_sync(dev->dev);