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

[Esben Haabendal <esben@geanix.com>]

"AngeloGioacchino Del Regno" <angelogioacchino.delregno@collabora.com>
writes:

> On 7/15/26 15:36, Gary Bisson wrote:
>> Hi,
>>
>> On Wed, Jul 15, 2026 at 03:25:11PM +0200, AngeloGioacchino Del Regno wrote:
>>> On 7/15/26 14:53, Esben Haabendal wrote:
>>>> Gary Bisson <bisson.gary@gmail.com> writes:
>>>>
>>>>> 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
>>>>>
>>>>> Move the necessary functions from enable to pre-enable.
>>>>>
>>>>> Signed-off-by: Gary Bisson <bisson.gary@gmail.com>
>>>>
>>>> Hi
>>>>
>>>> I have run into the same problem, but in combination with another
>>>> pipeline. I am seeing same problem with an i.MX8 using the nwl-dsi
>>>> bridge and the dcss driver.
>>>>
>>>> I have submitted a fix that adresses the problem in the ti-sn65dsi83
>>>> driver instead. With a bit of luck, it can replace the fix proposed in
>>>> this thread.
>>>>
>>>> See https://lore.kernel.org/all/20260711-ti-sn65dsi83-fixes-v1-2-d85eb5342b98@geanix.com/
>>
>> Thanks, just tried it on 7.2-rc3 with my patch reverted and confirm that
>> it works too. My assumption was that the SN65DSI83 was locking the PLL
>> earlier for some specific reason and therefore was reluctant to change
>> it.
>>
>>>> /Esben
>>>
>>> That clarifies a lot of things.
>>>
>>> The patch on mtk_dsi shall be reverted then.
>>
>> Angelo, do you want me to offer the revert patch? Should I wait to see
>> how the other thread goes?
>>
>
> Gary, yes please, send a revert and make sure to explain the reason why
> we're reverting this in the commit description :-)

Maybe test if my fix actually solves the problem with the mtk_dsi driver
also ;)

/Esben