[PATCH 2/2] drm/bridge: lt9611: Do not generate HFP/HBP/HSA and EOT packet

[Jagan Teki]

On Wed, Jul 5, 2023 at 11:09 AM Dmitry Baryshkov
<dmitry.baryshkov at linaro.org> wrote:
>
> [Adding freedreno@ to cc list]
>
> On Wed, 5 Jul 2023 at 08:31, Jagan Teki <jagan at amarulasolutions.com> wrote:
> >
> > Hi Amit,
> >
> > On Wed, Jul 5, 2023 at 10:15 AM Amit Pundir <amit.pundir at linaro.org> wrote:
> > >
> > > Hi Marek,
> > >
> > > On Wed, 5 Jul 2023 at 01:48, Marek Vasut <marex at denx.de> wrote:
> > > >
> > > > Do not generate the HS front and back porch gaps, the HSA gap and
> > > > EOT packet, as these packets are not required. This makes the bridge
> > > > work with Samsung DSIM on i.MX8MM and i.MX8MP.
> > >
> > > This patch broke display on Dragonboard 845c (SDM845) devboard running
> > > AOSP. This is what I see
> > > https://people.linaro.org/~amit.pundir/db845c-userdebug/v6.5-broken-display/PXL_20230704_150156326.jpg.
> > > Reverting this patch fixes this regression for me.
> >
> > Might be msm dsi host require proper handling on these updated
> > mode_flags? did they?
>
> The msm DSI host supports those flags. Also, I'd like to point out
> that the patch didn't change the rest of the driver code. So even if
> drm/msm ignored some of the flags, it should not have caused the
> issue. Most likely the issue is on the lt9611 side. I's suspect that
> additional programming is required to make it work with these flags.

True, But I'm not quite sure, most of these mode_flags were handled
more on the host. Maybe Marek can comment on this.

Thanks,
Jagan.