Re: [PATCH 2/2] drm/msm/dpu: Fix timeout issues on command mode panels

[AngeloGioacchino Del Regno]

Il 10/09/21 23:48, Marijn Suijten ha scritto:
> Hi Angelo!
>
> On 2021-09-01 19:43:47, AngeloGioacchino Del Regno wrote:
> > In function dpu_encoder_phys_cmd_wait_for_commit_done we are always
> > checking if the relative CTL is started by waiting for an interrupt
> > to fire: it is fine to do that, but then sometimes we call this
> > function while the CTL is up and has never been put down, but that
> > interrupt gets raised only when the CTL gets a state change from
> > 0 to 1 (disabled to enabled), so we're going to wait for something
> > that will never happen on its own.
> >
> > Solving this while avoiding to restart the CTL is actually possible
> > and can be done by just checking if it is already up and running
> > when the wait_for_commit_done function is called: in this case, so,
> > if the CTL was already running, we can say that the commit is done
> > if the command transmission is complete (in other terms, if the
> > interface has been flushed).
> >
> > Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxxx>
> > ---
> >   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c | 3 +++
> >   1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
> > index aa01698d6b25..b5b1b555ac4e 100644
> > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
> > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
> > @@ -682,6 +682,9 @@ static int dpu_encoder_phys_cmd_wait_for_commit_done(
> >   	if (!dpu_encoder_phys_cmd_is_master(phys_enc))
> >   		return 0;
> >   
> > +	if (phys_enc->hw_ctl->ops.is_started)
> > +		return dpu_encoder_phys_cmd_wait_for_tx_complete(phys_enc);
>
> In the previous commit you introduced is_started to the ops struct as
> function pointer, and you probably intend to call it here instead of
> just checking whether it might be NULL.
>
> As far as I remember this was also the reason for previously mentioning
> that it was faulty and required a v2 in:
> https://lore.kernel.org/linux-arm-msm/bdc67afc-3736-5497-c43f-5165c55e0354@xxxxxxxxxxxxxx/
>
> Thanks!
>
> - Marijn

Ugh. I've pulled this from the wrong tree.
Sending a v2 asap.

> > +
> >   	return _dpu_encoder_phys_cmd_wait_for_ctl_start(phys_enc);
> >   }
> >   
> > --
> > 2.32.0