Re: [PATCH 6.12.y] drm/amd/display: Reduce accessing remote DPCD overhead

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Feb 04, 2025 at 06:13:36PM +0800, Wayne Lin wrote:
> [Why]
> Observed frame rate get dropped by tool like glxgear. Even though the
> output to monitor is 60Hz, the rendered frame rate drops to 30Hz lower.
> 
> It's due to code path in some cases will trigger
> dm_dp_mst_is_port_support_mode() to read out remote Link status to
> assess the available bandwidth for dsc maniplation. Overhead of keep
> reading remote DPCD is considerable.
> 
> [How]
> Store the remote link BW in mst_local_bw and use end-to-end full_pbn
> as an indicator to decide whether update the remote link bw or not.
> 
> Whenever we need the info to assess the BW, visit the stored one first.
> 
> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3720
> Fixes: fa57924c76d9 ("drm/amd/display: Refactor function dm_dp_mst_is_port_support_mode()")
> Cc: Mario Limonciello <mario.limonciello@amd.com>
> Cc: Alex Deucher <alexander.deucher@amd.com>
> Reviewed-by: Jerry Zuo <jerry.zuo@amd.com>
> Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
> Signed-off-by: Tom Chung <chiahsuan.chung@amd.com>
> Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
> (cherry picked from commit 4a9a918545455a5979c6232fcf61ed3d8f0db3ae)
> Cc: stable@vger.kernel.org
> (cherry picked from commit adb4998f4928a17d91be054218a902ba9f8c1f93)

I'm confused, which commit is this exactly?  Both of these seem to be
the same, and you can't have 2 "cherry picked from" lines in a commit,
right?

thanks,

greg k-h