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

[Rosen Penev]

On Mon, Mar 30, 2026 at 7:21 AM Timur Kristóf <timur.kristof@xxxxxxxxx> wrote:
>
> 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@xxxxxxxxx>
> > >>
> > >> [ 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@xxxxxxxxx>
> > >> Reviewed-by: Rodrigo Siqueira <siqueira@xxxxxxxxxx>
> > >> Reviewed-by: Alex Deucher <alexander.deucher@xxxxxxx>
> > >> Reviewed-by: Alex Hung <alex.hung@xxxxxxx>
> > >> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
> > >> Signed-off-by: Rosen Penev <rosenp@xxxxxxxxx>
> > >
> > > 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.
Not sure what the process is here. I make sure everything can be git
cherry-pick ed. In that case, both should be present.
>
> >
> > >> ---
> > >>
> > >>  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)
>
>
>
>