Re: [PATCH v10 1/6] drm/bridge: cadence: cdns-mhdp8546-core: Set the mhdp connector earlier in atomic_enable()

[Luca Ceresoli]

On Tue Dec 9, 2025 at 1:03 PM CET, Harikrishna Shenoy wrote:
> From: Jayesh Choudhary <j-choudhary@xxxxxx>
>
> In case if we get errors in cdns_mhdp_link_up() or cdns_mhdp_reg_read()
> in atomic_enable, we will go to cdns_mhdp_modeset_retry_fn() and will hit
> NULL pointer while trying to access the mutex. We need the connector to
> be set before that. Unlike in legacy cases with flag
> !DRM_BRIDGE_ATTACH_NO_CONNECTOR, we do not have connector initialised
> in bridge_attach(), so add the mhdp->connector_ptr in device structure
> to handle both cases with DRM_BRIDGE_ATTACH_NO_CONNECTOR and
> !DRM_BRIDGE_ATTACH_NO_CONNECTOR, set it in atomic_enable() earlier to
> avoid possible NULL pointer dereference in recovery paths like
> modeset_retry_fn() with the DRM_BRIDGE_ATTACH_NO_CONNECTOR flag set.
>
> Fixes: c932ced6b585 ("drm/tidss: Update encoder/bridge chain connect model")
> Signed-off-by: Jayesh Choudhary <j-choudhary@xxxxxx>
> Signed-off-by: Harikrishna Shenoy <h-shenoy@xxxxxx>

Reviewed-by: Luca Ceresoli <luca.ceresoli@xxxxxxxxxxx>

--
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com