Re: [PATCH] drm/panel: himax-hx83102: restore MODE_LPM after sending disable cmds

[Doug Anderson]

Hi,

On Tue, Apr 28, 2026 at 8:53 AM Icenowy Zheng <zhengxingda@xxxxxxxxxxx> wrote:
>
> 在 2026-04-28二的 08:48 -0700，Doug Anderson写道：
> > Hi,
> >
> > On Mon, Apr 27, 2026 at 10:49 PM Icenowy Zheng
> > <zhengxingda@xxxxxxxxxxx> wrote:
> > >
> > > 在 2026-04-27一的 11:24 -0700，Doug Anderson写道：
> > > > Hi,
> > > >
> > > > On Sat, Apr 25, 2026 at 9:58 AM Icenowy Zheng
> > > > <zhengxingda@xxxxxxxxxxx> wrote:
> > > > >
> > > > > When preparing the panel, it seems that it always expects
> > > > > commands
> > > > > to be
> > > > > transferred in LP mode. However, the disable function removes
> > > > > the
> > > > > MIPI_DSI_MODE_LPM flag, and no other function re-adds it.
> > > > >
> > > > > As the unprepare function contains no DSI commands, re-adding
> > > > > the
> > > > > flag
> > > > > just after disabling the panel should be safe. Add the code re-
> > > > > adding
> > > > > the flag after the two commands for disabling the panel are
> > > > > sent.
> > > > >
> > > > > This fixes screen unblanking (after blanking once) on
> > > > > mt8188-geralt-ciri-sku1 device.
> > > > >
> > > > > Cc: stable@xxxxxxxxxxxxxxx # 6.11+
> > > > > Fixes: 0ef94554dc40 ("drm/panel: himax-hx83102: Break out as
> > > > > separate driver")
> > > >
> > > > This "Fixes" looks wrong. The bug was still there even before the
> > > > driver was broken out. ...and it looks like the driver that this
> > > > was
> > > > broken out of (panel-boe-tv101wum-nl6.c) still has the same bug?
> > >
> > > Yes, but I think the fix shouldn't be propagated to the other
> > > driver
> > > because of the same reason with breaking out the original driver.
> >
> > ...but doesn't all the same logic apply to the other driver? Nothing
> > ever adds MIPI_DSI_MODE_LPM back in.
> >
> > Even if you don't fix the other driver yourself right now, the proper
> > "Fixes" tag is when the problem was introduced, not when the driver
> > forked out.
>
> I think the Fixes tag should point to where the driver is forked out,
> and if I'm going to send a patch for panel-boe-tv101wum-nl6, it will
> has a Fixes tag pointing to the further commit affecting that driver.

You're free to have your own opinion, but that doesn't match my
understanding of the Fixes tag. If you can convince Neil or some other
drm-misc committer to land your changes with the Fixes tag as you have
it, then I won't object, but I won't land it. Best of luck!

-Doug