Thread (22 messages) 22 messages, 8 authors, 14h ago

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

From: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Date: 2026-07-15 13:40:42
Also in: dri-devel, linux-mediatek, lkml

On 7/15/26 15:36, Gary Bisson wrote:
Hi,

On Wed, Jul 15, 2026 at 03:25:11PM +0200, AngeloGioacchino Del Regno wrote:
quoted
On 7/15/26 14:53, Esben Haabendal wrote:
quoted
Gary Bisson [off-list ref] writes:
quoted
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 <redacted>
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/ (local)
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.
quoted
quoted
/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 :-)

Cheers,
Angelo
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