[PATCH] drm/amd/display: Look at firmware version to determine using dmub on dcn21

[Alex Deucher]

On Fri, Oct 29, 2021 at 4:19 PM Alex Deucher <alexdeucher at gmail.com> wrote:
>
> On Fri, Oct 29, 2021 at 4:12 PM Mario Limonciello
> <mario.limonciello at amd.com> wrote:
> >
> > commit b1c61212d8dc ("drm/amd/display: Fully switch to dmub for all dcn21
> > asics") switched over to using dmub on Renoir to fix Gitlab 1735, but this
> > implied a new dependency on newer firmware which might not be met on older
> > kernel versions.
> >
> > Since sw_init runs before hw_init, there is an opportunity to determine
> > whether or not the firmware version is new to adjust the behavior.
> >
> > Cc: Roman.Li at amd.com
> > BugLink: https://gitlab.freedesktop.org/drm/amd/-/issues/1772
> > BugLink: https://gitlab.freedesktop.org/drm/amd/-/issues/1735
> > Fixes: b1c61212d8dc ("drm/amd/display: Fully switch to dmub for all dcn21 asics")
> > Signed-off-by: Mario Limonciello <mario.limonciello at amd.com>
>
> Acked-by: Alex Deucher <alexander.deucher at amd.com>

Actually if there are version differences between renoir and green
sardine, maybe we need to bring back the old logic.  E.g.,
if (ASICREV_IS_GREEN_SARDINE(adev->external_rev_id))
    init_data.flags.disable_dmcu = true;
else
    init_data.flags.disable_dmcu = adev->dm.dmcub_fw_version > 0x01000000;

Alex

>
> > ---
> >  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > index 6dd6262f2769..85b3de97f870 100644
> > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > @@ -1410,7 +1410,7 @@ static int amdgpu_dm_init(struct amdgpu_device *adev)
> >                 switch (adev->ip_versions[DCE_HWIP][0]) {
> >                 case IP_VERSION(2, 1, 0):
> >                         init_data.flags.gpu_vm_support = true;
> > -                       init_data.flags.disable_dmcu = true;
> > +                       init_data.flags.disable_dmcu = adev->dm.dmcub_fw_version > 0x01000000;
> >                         break;
> >                 case IP_VERSION(1, 0, 0):
> >                 case IP_VERSION(1, 0, 1):
> > --
> > 2.25.1
> >