[PATCH 0/3] DC: Fix page flip timeouts on DCE 6

[Alex Deucher]

On Sat, Aug 2, 2025 at 12:23 PM Timur Kristóf <timur.kristof at gmail.com> wrote:
>
> Currently when using DC on DCE 6, it produces a page flip timeout
> after a suspend/resume.
>
> After some investigation, it turns out that the issue is because
> DC uses different interrupts between DCE 6 and newer HW versions,
> and it assumes that the VUPDATE interrupt is always present, when
> in fact it's not. It also assumes that the HW is capable of VRR
> when a VRR capable monitor is plugged in, when in fact this is
> not the case.
>
> This series marks VRR as unsupported on DCE 6 even when a VRR
> capable monitor is plugged in. Furthermore, it fixes the code
> trying to access the unregistered VUPDATE interrupt.
>
> As a side note, I also attempted to actually use the same
> interrupts as newer DCE versions, but this didn't work.
> Apparently DCE 6 was not advertised with VRR support anyway.
>
> Finally, there is also a patch to disable fast boot mode
> on DCE 6. The rationale is that this already didn't work
> on DCE 8, and even if it did I have no means to test it.
>
> Timur Kristóf (3):
>   drm/amd/display: Disable fastboot on DCE 6 too.
>   drm/amd/display: Disable VRR on DCE 6
>   drm/amd/display: Don't use non-registered VUPDATE on DCE 6

Series looks good to me, but it would be good to get an ack from the
display team as well.  Series is:
Acked-by: Alex Deucher <alexander.deucher at amd.com>

>
>  .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 26 ++++++++++++-------
>  .../amd/display/amdgpu_dm/amdgpu_dm_crtc.c    | 16 +++++++-----
>  drivers/gpu/drm/amd/display/dc/dc_helper.c    |  5 ++++
>  drivers/gpu/drm/amd/display/dc/dm_services.h  |  2 ++
>  .../amd/display/dc/hwss/dce110/dce110_hwseq.c |  6 ++---
>  5 files changed, 35 insertions(+), 20 deletions(-)
>
> --
> 2.50.1
>