APPLIED Re: [PATCH 0/1][SRU][F/OEM-5.6] drm/i915/dp_mst - only read the base capability in DPCD.

[Timo Aaltonen]

On 3.11.2020 4.49, Koba Ko wrote:
> BugLink: https://bugs.launchpad.net/bugs/1902613
> 
> [Impact]
> Currently DRM driver assume the source device caps is higher than the MST device
> caps. With this commit, the statement would be broken.
> 
> e.g. the source device only support DP1.2 and the mst device support DP1.4.
> 
> The source device can't output the video to the external monitor on the docking station.
> 
> [Fix]
> Revert the previous patch and only read the base capability from DPCD.
> 
> [test]
> With the patch, The machine(DP1.2) connect with the external monitor on docking station(SC) and
> can output the video to the external monitor on docking station(SC-DP1.4).
> 
> [Regression Potential]
> Can't output 4k at 60hz on the docking station(SC).
> 
> Koba Ko (1):
>    Revert "UBUNTU: SAUCE: drm/dp_mst: Retrieve extended DPCD caps for
>      topology manager"
> 
>   drivers/gpu/drm/drm_dp_mst_topology.c | 6 +++---
>   1 file changed, 3 insertions(+), 3 deletions(-)
> 

applied to oem-5.6

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