Re: [PATCH v2 0/7] drm/bridge: tc358768: Long command support

From: Tomi Valkeinen

Date: Wed May 06 2026 - 03:55:21 EST


Hi all,

On 11/03/2026 09:48, Tomi Valkeinen wrote:
This series makes some small improvements to the tc358768 driver, and
then adds support for long commands, commands that have more than 8
bytes of payload.

This has been tested on Toradex Verdin AM62 board, with a ST7703 based
DSI panel which requires initial configuration using commands that have
8+ bytes.

I tested the following combinations, by observing the panel visually and
the DSI lanes with an oscilloscope:

- HS command transfer, continuous clock
- HS command transfer, non-continuous clock
- LP command transfer, continuous clock
- LP command transfer, non-continuous clock

All except LP + continuous clock work fine. While observing the lanes
with normal oscilloscope is a very high level and vague view of what
exactly is going on the lanes, it still looks good to me: initial
commands are sent in LP, and then video data is being sent in HS, and
clock lane is continuous. However, the panel stays black, so something
is not quite right.

As it doesn't make sense to send commands in LP during initial
configuration, especially with longer commands, I will leave that
particular combination unresolved. I'd be interested to hear if it works
on some other panel.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
---
Changes in v2:
- Add reviewed-by & tested-by tags
- Rebase on v7.0-rc2
- Link to v1: https://lore.kernel.org/r/20251021-tc358768-v1-0-d590dc6a1a0c@xxxxxxxxxxxxxxxx
Any further comments from anyone? I don't see a specific maintainer for this bridge chip, so if there are no comments I'll push this to drm-misc in the coming days.

Tomi