On Mon, Jun 8, 2026 at 1:16 PM Liu Ying <[email protected]> wrote:
>
> On Fri, Jun 05, 2026 at 05:41:05PM +0530, Piyush Patle wrote:
> > Hi Marek, Liu Ying,
>
> Hi,

Hi Ying,
Thanks for the detailed update.

>
> >
> > I brought this series up on the i.MX95 15x15 FRDM (IT6263 LVDS-to-HDMI on
> > LVDS ch1). It mostly works, but I ran into a few issues around DI routing,
> > LVDS format handling, and DC enable sequencing which needed rework before
> > HDMI would come up reliably on the board.
> >
> > I don't see a v2 of the series and things seem to have been quiet since
> > November. Are you planning to post an updated version?
>
> My plan was to enable prefetch engine support[1] for i.MX8QXP display
> controller and add device tree for a whole i.MX8QXP LVDS display pipeline,
> before adding i.MX95 display controller support.
>
> Unfortunately, it seems that Marek is not a big fan of [1] and I'm busy
> with downstream development so the plan doesn't move forward well.  I still
> think [1] makes sense(maybe I need to rebase it on latest drm-misc-next),
> so I'd like to see review comments on [1] and hopefully people think that
> the overall idea of [1] is ok.
>
> >
> > I've accumulated a fair amount of rework while getting this running on the
> > FRDM. If you're not planning a v2, I can clean things up and send one based
> > on the current series.
>
> I still think that i.MX95 display controller driver should be in a separate
> driver, rather than sharing the same driver with i.MX8QXP display controller
> like this patch series does, because the two display controllers are quite
> different as I mentioned in comments on this patch series and in discussion
> in [1].  Also, the common part between the two display controllers should
> be extracted to a common helper library as I mentioned there too.
>
I agree with your direction. A separate i.MX95 DC driver with the common pieces
factored into a shared helper library seems like a better long-term
approach than
extending the i.MX8QXP driver, given how different the two controllers are.

> >
> > Thanks,
> > Piyush
>
> [1] lore.kernel.org/all/[email protected]/
>
I've had the current series running on the i.MX95 15x15 FRDM (IT6263
LVDS-to-HDMI
on LVDS channel 1). HDMI now comes up reliably and remains stable. The mode
and timing are correct (1280x720@60), the LVDS/LDB pixel clock is at
74.25 MHz in
single-link mode, and the DC plane is scanning out a linear XRGB8888
buffer correctly

The one issue I'm still chasing is color. Timing and sync look
correct, but the colors on
screen are wrong. I've ruled out a few obvious causes and see the same
result with a
simple CPU-generated test pattern, so it doesn't appear to be GPU or
Mesa related.
I'm currently narrowing the root cause and will report back once I find it.

While bringing the series up on the FRDM, I ended up reworking three main areas:
- DI routing (display interface selection and pixel-link to LVDS channel wiring)
- LVDS bus-format handling
- DC enable sequencing

I have time available to help move this forward. I'm happy to continue
testing on the
FRDM and provide feedback on the reworks I've made.

On the other hand, if additional help would be useful, I'd be
interested in working on the
separate i.MX95 driver under your guidance and posting the resulting
series for review.
If that sounds reasonable, I'd be glad to coordinate with you on how
you'd like the work
structured.

I'll also take a look at the prefetch engine series! Thanks again.

> --
> Regards,
> Liu Ying

Thanks,
Piyush

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