Re: [PATCH 2/2] drm/bridge: ti-sn65dsi86: retrain DP link directly on cable replug

[Doug Anderson]

Hi,

On Fri, Aug 14, 2026 at 5:04 AM Yashas D <y-d@xxxxxx> wrote:
>
> When a cable is replugged while the upstream display pipeline is still
> active (e.g. a compositor holds the CRTC), the bridge can retrain the
> DP link and re-enable the video stream directly from the HPD interrupt
> work handler without requiring a full DRM atomic commit. This allows
> applications to recover display output after a cable replug.
>
> Signed-off-by: Yashas D <y-d@xxxxxx>
> ---
>  drivers/gpu/drm/bridge/ti-sn65dsi86.c | 215 +++++++++++++++++++++-----
>  1 file changed, 179 insertions(+), 36 deletions(-)

There's a lot of code here and Sashiko has a bunch of feedback [1].
I'm not personally very familiar with the HPD flows. I'll probably
skip reviewing this until Sashiko is reasonably happy or until you
explain why Sashiko is confused.

FWIW, just from the patch description, I'd also question if this is
really a good idea. If we get an unplug / replug, we could get an
entirely new display plugged in. This is really something that's OK
without needing to handle things?


[1] https://lore.kernel.org/all/20260814121431.72C701F000E9@xxxxxxxxxxxxxxx/