Display Port handling errors out when monitor is slow to wake up

[Alex Deucher]

On Wed, Apr 30, 2025 at 3:55 AM Borislav Petkov <bp at alien8.de> wrote:
>
> + amdgpu folks.
>
> On Tue, Apr 29, 2025 at 02:51:21PM +0200, Marcus Rückert wrote:
> > Hardware:
> > - ASUS ROG Swift OLED PG27AQDP
> > - XFX Mercury Radeon RX 9070 XT OC Gaming Edition with RGB, 16GB GDDR6, HDMI, 3x DP RX-97TRGBBB9
> >
> > Kernel:
> > - kernel-default-6.15~rc4-1.1.g62ec7c7.x86_64 from https://build.opensuse.org/project/show/Kernel:HEAD
> >
> > The monitor is really slow on waking up - or even switching mode e.g. when going from console to wayland with 480Hz.
> > When I turn on the monitor before I wake up wayland via keyboard/mouse, no error comes. If I wake up wayland first and then start the monitor:

Ideally you would physically turn the monitor on before you wake the
desktop.  Even better, just let the compositor manage the monitor.  It
will turn the monitor off automatically after an idle period.  If you
try to use the desktop before the monitor is powered up, the driver is
not able to train the link with the monitor because the monitor is
powered off, hence the errors below.  That can also lead to delays as
the driver attempts to train the link, but since the monitor is off,
it leads to lots of timeouts and failures until the monitor is
actually powered on.  Is those suggestions don't help, please file a
report here:
https://gitlab.freedesktop.org/drm/amd/-/issues/

Thanks,

Alex

> >
> > ```
> > [Tue Apr 29 13:49:54 2025] [  T70365] amdgpu 0000:03:00.0: [drm] *ERROR* dpcd_set_link_settings:1118: core_link_write_dpcd (DP_DOWNSPREAD_CTRL) failed
> > [Tue Apr 29 13:49:54 2025] [  T70365] amdgpu 0000:03:00.0: [drm] *ERROR* dpcd_set_link_settings:1123: core_link_write_dpcd (DP_LANE_COUNT_SET) failed
> > [Tue Apr 29 13:49:54 2025] [  T70365] amdgpu 0000:03:00.0: [drm] *ERROR* dpcd_set_link_settings:1151: core_link_write_dpcd (DP_LINK_BW_SET) failed
> > [Tue Apr 29 13:49:55 2025] [  T70365] amdgpu 0000:03:00.0: [drm] *ERROR* dpcd_set_link_settings:1118: core_link_write_dpcd (DP_DOWNSPREAD_CTRL) failed
> > [Tue Apr 29 13:49:55 2025] [  T70365] amdgpu 0000:03:00.0: [drm] *ERROR* dpcd_set_link_settings:1123: core_link_write_dpcd (DP_LANE_COUNT_SET) failed
> > [Tue Apr 29 13:49:55 2025] [  T70365] amdgpu 0000:03:00.0: [drm] *ERROR* dpcd_set_link_settings:1151: core_link_write_dpcd (DP_LINK_BW_SET) failed
> > [Tue Apr 29 13:49:56 2025] [  T70365] amdgpu 0000:03:00.0: [drm] *ERROR* dpcd_set_link_settings:1118: core_link_write_dpcd (DP_DOWNSPREAD_CTRL) failed
> > [Tue Apr 29 13:49:56 2025] [  T70365] amdgpu 0000:03:00.0: [drm] *ERROR* dpcd_set_link_settings:1123: core_link_write_dpcd (DP_LANE_COUNT_SET) failed
> > [Tue Apr 29 13:49:56 2025] [  T70365] amdgpu 0000:03:00.0: [drm] *ERROR* dpcd_set_link_settings:1151: core_link_write_dpcd (DP_LINK_BW_SET) failed
> > [Tue Apr 29 13:49:57 2025] [  T70365] amdgpu 0000:03:00.0: [drm] *ERROR* dpcd_set_link_settings:1118: core_link_write_dpcd (DP_DOWNSPREAD_CTRL) failed
> > [Tue Apr 29 13:49:57 2025] [  T70365] amdgpu 0000:03:00.0: [drm] *ERROR* dpcd_set_link_settings:1123: core_link_write_dpcd (DP_LANE_COUNT_SET) failed
> > [Tue Apr 29 13:49:57 2025] [  T70365] amdgpu 0000:03:00.0: [drm] *ERROR* dpcd_set_link_settings:1151: core_link_write_dpcd (DP_LINK_BW_SET) failed
> > [Tue Apr 29 13:49:58 2025] [  T70365] amdgpu 0000:03:00.0: [drm] enabling link 1 failed: 15
> > ```
> >
> > Feel free to ping me if you need more information.
> >
> >    darix
> >
> > ```
> > --
> > Always remember:
> >   Never accept the world as it appears to be.
> >     Dare to see it for what it could be.
> >       The world can always use more heroes.
> >
> >
> >
> >
> > ```
> >
>
> --
> Regards/Gruss,
>     Boris.
>
> https://people.kernel.org/tglx/notes-about-netiquette