Re: [PATCH v4 00/24] drm/bridge: Make panel and bridge probe order consistent

[John Stultz]

On Wed, Sep 29, 2021 at 2:51 PM John Stultz <john.stultz@xxxxxxxxxx> wrote:
>
> On Wed, Sep 29, 2021 at 2:32 PM John Stultz <john.stultz@xxxxxxxxxx> wrote:
> > On Wed, Sep 29, 2021 at 2:27 PM John Stultz <john.stultz@xxxxxxxxxx> wrote:
> > > On Fri, Sep 10, 2021 at 3:12 AM Maxime Ripard <maxime@xxxxxxxxxx> wrote:
> > > > The best practice to avoid those issues is to register its functions only after
> > > > all its dependencies are live. We also shouldn't wait any longer than we should
> > > > to play nice with the other components that are waiting for us, so in our case
> > > > that would mean moving the DSI device registration to the bridge probe.
> > > >
> > > > I also had a look at all the DSI hosts, and it seems that exynos, kirin and msm
> > > > would be affected by this and wouldn't probe anymore after those changes.
> > > > Exynos and kirin seems to be simple enough for a mechanical change (that still
> > > > requires to be tested), but the changes in msm seemed to be far more important
> > > > and I wasn't confortable doing them.
> > >
> > >
> > > Hey Maxime,
> > >   Sorry for taking so long to get to this, but now that plumbers is
> > > over I've had a chance to check it out on kirin
> > >
> > > Rob Clark pointed me to his branch with some fixups here:
> > >    https://gitlab.freedesktop.org/robclark/msm/-/commits/for-mripard/bridge-rework
> > >
> > > But trying to boot hikey with that, I see the following loop indefinitely:
> > > [    4.632132] adv7511 2-0039: supply avdd not found, using dummy regulator
> > > [    4.638961] adv7511 2-0039: supply dvdd not found, using dummy regulator
> > > [    4.645741] adv7511 2-0039: supply pvdd not found, using dummy regulator
> > > [    4.652483] adv7511 2-0039: supply a2vdd not found, using dummy regulator
> > > [    4.659342] adv7511 2-0039: supply v3p3 not found, using dummy regulator
> > > [    4.666086] adv7511 2-0039: supply v1p2 not found, using dummy regulator
> > > [    4.681898] adv7511 2-0039: failed to find dsi host
> >
> > I just realized Rob's tree is missing the kirin patch. My apologies!
> > I'll retest and let you know.
>
> Ok, just retested including the kirin patch and unfortunately I'm
> still seeing the same thing.  :(
>
> Will dig a bit and let you know when I find more.

Hey Maxime!
  I chased down the issue. The dsi probe code was still calling
drm_of_find_panel_or_bridge() in order to succeed.

I've moved the logic that looks for the bridge into the bridge_init
and with that it seems to work.

Feel free (assuming it looks ok) to fold this change into your kirin patch:
  https://git.linaro.org/people/john.stultz/android-dev.git/commit/?id=4a35ccc4d7a53f68d6d93da3b47e232a7c75b91d

thanks
-john