Re: [PATCH v9 0/6] MHDP8546 fixes related to DBANC usecase

[Maxime Ripard]

Hi,

On Tue, Nov 18, 2025 at 05:22:49PM +0530, Harikrishna Shenoy wrote:
> With the DBANC framework, the connector is no longer initialized in 
> bridge_attach() when the display controller sets the 
> DRM_BRIDGE_ATTACH_NO_CONNECTOR flag. 
> This causes a null pointer dereference in cdns_mhdp_modeset_retry_fn() 
> when trying to access &conn->dev->mode_config.mutex. 
> Observed on a board where EDID read failed. 
> (log: https://gist.github.com/Jayesh2000/233f87f9becdf1e66f1da6fd53f77429)
> 
> Patch 1 adds a connector_ptr which takes care of both 
> DBANC and !DBANC case by setting the pointer in appropriate hooks
> and checking for pointer validity before accessing the connector.
> Patch 2 adds mode validation hook to bridge fucntions.
> Patch 3 fixes HDCP to work with both DBANC and !DBANC case by
> moving HDCP state handling into the bridge atomic check in line with 
> the DBANC model.
> Patches 4,5 do necessary cleanup and alignment for using
> connector pointer.

It's mentioned several times in your series, and it might be obvious to
you, but documenting what is the "DBANC framework" is would be helpful.
I have no idea what it's about, and it appears that Google doesn't know
either.

Maxime

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