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

[Tomi Valkeinen]

Hi,

On 09/12/2025 14:03, 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>
> ---
>  .../drm/bridge/cadence/cdns-mhdp8546-core.c   | 29 ++++++++++---------
>  .../drm/bridge/cadence/cdns-mhdp8546-core.h   |  1 +
>  .../drm/bridge/cadence/cdns-mhdp8546-hdcp.c   | 18 +++++++++---
>  3 files changed, 30 insertions(+), 18 deletions(-)
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>

 Tomi