Re: [PATCH v6 00/12] platform/chrome: Introduce DT hardware prober

Chen-Yu Tsai
2024-09-09T03:24:29Z

On Sun, Sep 8, 2024 at 12:58 AM Wolfram Sang
<wsa+renesas@sang-engineering.com> wrote:
>
> Hi,
>
> this series gets quite some review from people I trust. This is awesome.
> So, I will keep to some high level questions:
>
> > undiscoverable devices" [2] series, but follows the scheme suggested by
> > Rob, marking all second source component device nodes as "fail-needs-probe",
> > and having a hardware prober driver enable the one of them.
>
> Where is this "fail-needs-probe" documented? I neither see it here nor
> in the dt-schema repo.

You are correct that it has not been documented yet. I will send a patch
to the dt-schema repo.

> > The other case, selecting a display panel to use based on the SKU ID
> > from the firmware, hit a bit of an issue with fixing the OF graph.
> > It has been left out since v3.
>
> Does it make sense then to add touchscreens only? Will the panels be
> worked on once this is upstream? Or what is the way forward?

The devices this patch series targets all use eDP panels, which are
more or less directly probe-able.

The panels mentioned for the second phase are MIPI panels, which require
specific power and command sequences and thus are not probe-able. This
will be worked on once this part is done. For the panels it is entirely
handled in the chrome platform device tree prober. See the following
patch for an earlier version of it:

https://lore.kernel.org/all/20231109100606.1245545-6-wenst@chromium.org/

> > Wolfram, would you be able to handle the late PR? Assuming you get a
> > chance to look at the patches that is.
>
> Yes, I can do this, but...
>
> > drivers/i2c/Makefile | 7 +-
> > drivers/i2c/i2c-core-of-prober.c | 437 ++++++++++++++++++
>
> ... this is quite some code. Would you be willing to maintain it (i.e.
> please add a MAINTAINERS entry then). Kudos for not touching other parts
> of the I2C core!

Sure!

> All the best,
>
> Wolfram

Thanks. There are still some comments to address, in particular making
the prober more of a pluggable framework and exposing more code as
helpers.

ChenYu