[PATCH 1/2] opos6uldev: make the LCD work again

[Tom Rini]

On Wed, Feb 28, 2024 at 10:09:13AM +0300, Dan Carpenter wrote:
> On Tue, Feb 27, 2024 at 04:40:01PM +0100, Sébastien Szymanski wrote:
> > Commit 5d7a95f49999 ("imx6ul/imx6ull: synchronise device trees with
> > linux") removed the display timings from the board device tree whereas
> > they are still needed by the mxsfb driver.
> > Add the timings back (the correct ones) in the
> > imx6ul-opos6uldev-u-boot.dtsi file and remove them from the
> > opos6uldev.env file.
> > 
> > Update the opos6uldev_defconfig file so that the LCD turns on at boot.
> > 
> > Fixes: 5d7a95f49999 ("imx6ul/imx6ull: synchronise device trees with linux")
> > Signed-off-by: Sébastien Szymanski <sebastien.szymanski at armadeus.com>
> 
> Huh.  This is the commit that did that upstream.
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d9aa4d4fca67823838fe9861456201430c545e69
> 
> It's interesting how the timings in linux were always slightly different
> from in u-boot.

Thanks for tracking that down, Dan. I'm adding in Sumit and Rob here
because this is a recent (rather than ancient) example of one of the
concerns about OF_UPSTREAM. I think the commit in question can be
summarized as "remove a bunch of explicit HW information because there's
now a Linux Kernel driver that determines that dynamically". What do we
do next? The old information is in a presumably valid binding still, can
we just put it back and comment that consumers outside of Linux use this
still so it's not removed again later? Or am I just missing where we can
instead get this information from the DT still and not need to come up
with a new driver and subsystems?

-- 
Tom
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