Re: [PATCH] drm/mediatek: mtk_dsi: enable hs clock during pre-enable

["CK Hu (胡俊光)" <ck.hu@mediatek.com>]

On Mon, 2026-07-06 at 12:16 +0200, Thorsten Leemhuis wrote:
> External email : Please do not click links or open attachments until you have verified the sender or the content.
> 
> 
> On 6/22/26 15:23, Adam Thiede wrote:
> > On 6/22/26 06:22, Gary Bisson wrote:
> > > On Thu, Jun 18, 2026 at 04:06:28PM -0500, Adam Thiede wrote:
> > > > On 1/20/26 05:36, Gary Bisson wrote:
> > > > > Some bridges, such as the TI SN65DSI83, require the HS clock to be
> > > > > running in order to lock its PLL during its own pre-enable function.
> > > > > 
> > > > > Without this change, the bridge gives the following error:
> > > > > sn65dsi83 14-002c: failed to lock PLL, ret=-110
> > > > > sn65dsi83 14-002c: Unexpected link status 0x01
> > > > > sn65dsi83 14-002c: reset the pipe
> > > > > [...]
> > > > 
> > > > This commit was part of 7.1 and caused a problem for me.
> > > > I'm running postmarketOS (basically Alpine Linux) on a Lenovo C330
> > > > chromebook with a Mediatek MT8173 processor.
> > > > The problem: when the display on my laptop powers off (via suspend or
> > > > idle,
> > > > like xset dpms off) the picture does not come back when the display
> > > > powers
> > > > back on (from resume). The display backlight comes on and brightness is
> > > > adjustable but there is no picture. The only fix is to reboot.
> > > > 
> > > > Reverting this commit and applying it as a patch on top of 7.1
> > > > addresses the
> > > > issue for me.
> > > > 
> > > > You can view the config I'm using here:
> > > > https://urldefense.com/v3/__https://gitlab.postmarketos.org/postmarketOS/pmaports/-/__;!!CTRNKA9wMg0ARbw!jrsPDtSEUdaINzLlq92Li8gmsEBkTOxZ6WUzNHjvIN6CyOJjHiHkNSOhIRPXFTLPlaYlxU2uvryVkwjUAN9bmax5$
> > > > merge_requests/8819
> > > > 
> > > > Is there any sort of testing or other debugging info I can provide to
> > > > help
> > > > address this issue?
> > > 
> > > Thanks for reporting the issue, could you share some logs? Is the driver
> > > saying anything during resume? Also, what type of panel is used on that
> > > chromebook?
> > 
> > The curious thing is that there are no real logs in dmesg or /var/log/
> > messages about this. This picture just fails to come back. If there are
> > some kernel params I can set to get deeper logging, that would help, but
> > I'm not aware of any.
> > 
> > I think the panel is a "BOE NV116WHM-T00" - I used this command to get
> > info: cat /sys/class/drm/card0-eDP-1/edid | edid-decode
> > 
> > Output: https://urldefense.com/v3/__https://termbin.com/8nbd__;!!CTRNKA9wMg0ARbw!jrsPDtSEUdaINzLlq92Li8gmsEBkTOxZ6WUzNHjvIN6CyOJjHiHkNSOhIRPXFTLPlaYlxU2uvryVkwjUAJooSyqL$
> 
> This looked stalled. If I'm mistaken here, please let me known; but if
> no solution is in sight, should we maybe just revert the change until a
> proper was found?
> 
> Ciao, Thorsten
> 
> 

It's welcome anyone to provide a revert patch,
but I would still wait for the fixup patch until 7.2-rc4.
If no fixup patch exist, then apply the revert patch.

Regards,
CK