Re: [PATCH for 6.12 3/9] drm/amd/display: Disable fastboot on DCE 6 too

["Timur Kristóf" <timur.kristof@gmail.com>]

On Monday, March 30, 2026 3:55:55 PM Central European Summer Time Christian 
König wrote:
> On 3/30/26 15:16, Timur Kristóf wrote:
> > On Friday, March 27, 2026 12:47:10 AM Central European Summer Time Rosen
> > Penev> 
> > wrote:
> >> From: Timur Kristóf <timur.kristof@gmail.com>
> >> 
> >> [ Upstream commit 7495962cbceb967e095233a5673ea71f3bcdee7e ]
> >> 
> >> It already didn't work on DCE 8,
> >> so there is no reason to assume it would on DCE 6.
> >> 
> >> Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
> >> Reviewed-by: Rodrigo Siqueira <siqueira@igalia.com>
> >> Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
> >> Reviewed-by: Alex Hung <alex.hung@amd.com>
> >> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
> >> Signed-off-by: Rosen Penev <rosenp@gmail.com>
> > 
> > This patch is incorrect and should not be backported.
> > 
> > (Note that the error is already fixed upstream. For stable kernels IMO
> > it's
> > best to drop this one.)
> 
> Is there some alternative which needs to be backported or should the old
> kernel just work out of the box because we never enabled some feature
> there?
> 
> Apart from that the patch set looks good to me.
> 

This patch had a typo and does the opposite of what it should, ie. it disables 
eDP fastboot on DCE10 and newer instead of disabling it on DCE8 and older.

The upstream fix is here:
https://lists.freedesktop.org/archives/amd-gfx/2026-February/138577.html
which disables eDP fastboot on DCE10 and older.

> 
> >> ---
> >> 
> >>  drivers/gpu/drm/amd/display/dc/hwss/dce110/dce110_hwseq.c | 6 ++----
> >>  1 file changed, 2 insertions(+), 4 deletions(-)
> >> 
> >> diff --git a/drivers/gpu/drm/amd/display/dc/hwss/dce110/dce110_hwseq.c
> >> b/drivers/gpu/drm/amd/display/dc/hwss/dce110/dce110_hwseq.c index
> >> df69e0cebf78..7dc99c85b8ea 100644
> >> --- a/drivers/gpu/drm/amd/display/dc/hwss/dce110/dce110_hwseq.c
> >> +++ b/drivers/gpu/drm/amd/display/dc/hwss/dce110/dce110_hwseq.c
> >> @@ -1910,10 +1910,8 @@ void dce110_enable_accelerated_mode(struct dc *dc,
> >> struct dc_state *context)
> >> 
> >>  	get_edp_streams(context, edp_streams, &edp_stream_num);
> >> 
> >> -	// Check fastboot support, disable on DCE8 because of blank
> > 
> > screens
> > 
> >> -	if (edp_num && edp_stream_num && dc->ctx->dce_version !=
> > 
> > DCE_VERSION_8_0
> > 
> >> && -		    dc->ctx->dce_version != DCE_VERSION_8_1 &&
> >> -		    dc->ctx->dce_version != DCE_VERSION_8_3) {
> >> +	/* Check fastboot support, disable on DCE 6-8 because of blank
> > 
> > screens */
> > 
> >> +	if (edp_num && edp_stream_num && dc->ctx->dce_version <
> > 
> > DCE_VERSION_10_0)
> > 
> >> { for (i = 0; i < edp_num; i++) {
> >> 
> >>  			edp_link = edp_links[i];
> >>  			if (edp_link != edp_streams[0]->link)