[PATCH 6.1.y] drm/amd/display: Don't refer to dc_sink in is_dsc_need_re_compute

[Greg KH]

On Wed, Dec 11, 2024 at 06:15:44PM +0800, jianqi.ren.cn at windriver.com wrote:
> From: Wayne Lin <wayne.lin at amd.com>
> 
> [ Upstream commit fcf6a49d79923a234844b8efe830a61f3f0584e4 ]
> 
> [Why]
> When unplug one of monitors connected after mst hub, encounter null pointer dereference.
> 
> It's due to dc_sink get released immediately in early_unregister() or detect_ctx(). When
> commit new state which directly referring to info stored in dc_sink will cause null pointer
> dereference.
> 
> [how]
> Remove redundant checking condition. Relevant condition should already be covered by checking
> if dsc_aux is null or not. Also reset dsc_aux to NULL when the connector is disconnected.
> 
> Reviewed-by: Jerry Zuo <jerry.zuo at amd.com>
> Acked-by: Zaeem Mohamed <zaeem.mohamed at amd.com>
> Signed-off-by: Wayne Lin <wayne.lin at amd.com>
> Tested-by: Daniel Wheeler <daniel.wheeler at amd.com>
> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
> Signed-off-by: Jianqi Ren <jianqi.ren.cn at windriver.com>
> ---
>  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c | 4 ++++
>  1 file changed, 4 insertions(+)

You sent this 3 times, all different, so I have no idea what to do.

Ok, I give up.  I'm deleting ALL of your pending stable patches from my
review queue now due to all of the problems that these have had.

Please work with a more experienced kernel developer at your company to
get these backports correct, and complete, and send them as a patch
series with the correct information and documentation as to what is
going on, so that we have a chance to get this right.

thanks,

greg k-h