Re: [PATCH 6.10] drm/amd/display: Refactor function dm_dp_mst_is_port_support_mode()

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Jul 30, 2024 at 08:53:39PM +0200, Kevin Holm wrote:
> From: Wayne Lin <wayne.lin@amd.com>
> 
> [ Upstream commit fa57924c76d995e87ca3533ec60d1d5e55769a27 ]
> 
> [Why]
> dm_dp_mst_is_port_support_mode() is a bit not following the original design rule and cause
> light up issue with multiple 4k monitors after mst dsc hub.
> 
> [How]
> Refactor function dm_dp_mst_is_port_support_mode() a bit to solve the light up issue.
> 
> Reviewed-by: Jerry Zuo <jerry.zuo@amd.com>
> Acked-by: Zaeem Mohamed <zaeem.mohamed@amd.com>
> Signed-off-by: Wayne Lin <wayne.lin@amd.com>
> Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
> [kevin@holm.dev: Resolved merge conflict in .../amdgpu_dm_mst_types.c]
> Fixes: 4df96ba6676034 ("drm/amd/display: Add timing pixel encoding for mst mode validation")
> Link: https://lore.kernel.org/stable/d74a7768e957e6ce88c27a5bece0c64dff132e24@holm.dev/T/#u
> Signed-off-by: Kevin Holm <kevin@holm.dev>
> ---
> I resolved the merge conflict so that, after this patch is applied to the
> linux-6.10.y branch of the stable git repository, the resulting function
> dm_dp_mst_is_port_support_mode (and also the new function 
> dp_get_link_current_set_bw) is identical to the original commit.
> 
> I've confirmed that it fixes the regression I reported for my use case.

And it turns out this change breaks the arm and arm64 builds.  I tried
to fix it up by applying the fixup afterward for this file, but it's
just too much of a mess to unwind this, so I'm going to have to revert
this now, sorry.

See:
	https://lore.kernel.org/r/b27c5434-f1b1-4697-985b-91bb3e9a22df@roeck-us.net
for details.

greg k-h