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

[Adam Thiede]

On 7/27/26 07:48, Gary Bisson wrote:
> Hi Thorsten,
> 
> On Mon, Jul 27, 2026 at 02:28:56PM +0200, Thorsten Leemhuis wrote:
>> [top-posting to facilitate]
>>
>> Gary, Angelo, what's the status here? It looks like this fell through
>> the cracks -- or was this issue fixed in between somehow? If yes: great!
>> If not: Would be good to finally resolve this, as we are long past "fix
>> within a week" rule of thumb from Linus:
>> https://www.kernel.org/doc/html/latest/process/handling-regressions.html#on-how-quickly-regressions-should-be-fixed
> 
> Not much happened I'm afraid. The status as I see is:
> - this patch is necessary to have TI SN65DSI83 working
> - this patch also follows the DRM guidelines saying that HS clock must
>    be enabled during pre_enable (see previous answer / [1])
> - this patch has been successfully tested against MIPI-DSI panels (by
>    Angelo) and LVDS panels via TI bridge (by myself)
> - Adam reported an issue with another bridge (PS8640) where resume is
>    broken
> - Esben offered a patch to the TI bridge that would fix the issue we
>    were seeing in the first place.
> 
> But for the last two points, I'm not sure this calls for a revert yet:
> - enabling HS clock in pre_enable still is what should be done [1]
> - maybe the issue Adam is facing is due to the bridge driver instead as
>    it could not be reproduced with another setup
> - Esben patch would break the SN65DSI83 init sequence, suggesting that
>    the culprit really is the MIPI bridge for not following the HS clock
>    requirement in pre_enable instead [2]
> 
> So if we agree on the fact that HS clock must be set during pre_enable
> then I don't see a reason to revert that commit.
> 
> Regards,
> Gary
> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/gpu/drm/drm_bridge.c#n169
> [2] https://patchwork.kernel.org/project/dri-devel/patch/20260711-ti-sn65dsi83-fixes-v1-2-d85eb5342b98@geanix.com/
I'm also happy to try out any patches and report back, too! Just point 
me to it and let me know which release/RC I should apply it to.