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

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

On Tuesday, March 31, 2026 1:03:34 PM Central European Summer Time Greg Kroah-
Hartman wrote:
> On Mon, Mar 30, 2026 at 02:38:35PM -0700, Rosen Penev wrote:
> > On Mon, Mar 30, 2026 at 7:21 AM Timur Kristóf <timur.kristof@gmail.com> 
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@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.
> > 
> > Not sure what the process is here. I make sure everything can be git
> > cherry-pick ed. In that case, both should be present.
> 
> I agree, I don't understand the problem here.  Just take the commits
> that are upstream including "fixes for the fixes".
> 
> Timur, what specifically do you want to see happen here?

Hi Greg,

It's up to you how you prefer to address this. I just wanted to call Rosen's 
attention to the above issue to avoid regressing the stable kernels.
I'm happy with either dropping the patch or backporting the patch together 
with its fix.

Thanks,
Timur