[PATCH 3/3] drm/amd/display: Compensate for pre-DCE12 BTR-VRR hw limitations. (v2)
Mario Kleiner
mario.kleiner.de at gmail.com
Fri Apr 26 21:43:57 UTC 2019
On Fri, Apr 26, 2019 at 7:12 PM Kazlauskas, Nicholas
<Nicholas.Kazlauskas at amd.com> wrote:
>
> On 4/26/19 6:50 AM, Mario Kleiner wrote:
> > Pre-DCE12 needs special treatment for BTR / low framerate
> > compensation for more stable behaviour:
> >
> > According to comments in the code and some testing on DCE-8
> > and DCE-11, DCE-11 and earlier only apply VTOTAL_MIN/MAX
> > programming with a lag of one frame, so the special BTR hw
> > programming for intermediate fixed duration frames must be
> > done inside the current frame at flip submission in atomic
> > commit tail, ie. one vblank earlier, and the fixed refresh
> > intermediate frame mode must be also terminated one vblank
> > earlier on pre-DCE12 display engines.
> >
> > To achieve proper termination on < DCE-12 shift the point
> > when the switch-back from fixed vblank duration to variable
> > vblank duration happens from the start of VBLANK (vblank irq,
> > as done on DCE-12+) to back-porch or end of VBLANK (handled
> > by vupdate irq handler). We must leave the switch-back code
> > inside VBLANK irq for DCE12+, as before.
> >
> > Doing this, we get much better behaviour of BTR for up-sweeps,
> > ie. going from short to long frame durations (~high to low fps)
> > and for constant framerate flips, as tested on DCE-8 and
> > DCE-11. Behaviour is still not quite as good as on DCN-1
> > though.
> >
> > On down-sweeps, going from long to short frame durations
> > (low fps to high fps) < DCE-12 is a little bit improved,
> > although by far not as much as for up-sweeps and constant
> > fps.
> >
> > v2: Fix some wrong locking, as pointed out by Nicholas.
> > Signed-off-by: Mario Kleiner <mario.kleiner.de at gmail.com>
>
> Still looks good to me, but I just noticed one other minor nitpick (sorry!)
>
> > ---
> > .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 45 +++++++++++++++++--
> > 1 file changed, 42 insertions(+), 3 deletions(-)
> >
> > 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 76b6e621793f..7241e1f3ebec 100644
> > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > @@ -364,6 +364,7 @@ static void dm_vupdate_high_irq(void *interrupt_params)
> > struct amdgpu_device *adev = irq_params->adev;
> > struct amdgpu_crtc *acrtc;
> > struct dm_crtc_state *acrtc_state;
> > + unsigned long flags;
> >
> > acrtc = get_crtc_by_otg_inst(adev, irq_params->irq_src - IRQ_TYPE_VUPDATE);
> >
> > @@ -381,6 +382,22 @@ static void dm_vupdate_high_irq(void *interrupt_params)
> > */
> > if (amdgpu_dm_vrr_active(acrtc_state))
> > drm_crtc_handle_vblank(&acrtc->base);
>
> Can't this block be merged with the one below?
>
> With the condition also changed to just:
>
> if (acrtc_state->stream && adev->family < AMDGPU_FAMILY_AI)
> ...
Done. New series out, retested.
-mario
>
> I also noticed that the crtc_state itself is always accessed unlocked
> for checking whether VRR is on/off which is probably a bug... but this
> patch shouldn't be the one to fix that. At the very least though it can
> leave things in a bit better shape like you've already done. Thanks!
>
> Nicholas Kazlauskas
>
> > +
> > + if (acrtc_state->stream && adev->family < AMDGPU_FAMILY_AI &&
> > + acrtc_state->vrr_params.supported &&
> > + acrtc_state->freesync_config.state == VRR_STATE_ACTIVE_VARIABLE) {
> > + spin_lock_irqsave(&adev->ddev->event_lock, flags);
> > + mod_freesync_handle_v_update(
> > + adev->dm.freesync_module,
> > + acrtc_state->stream,
> > + &acrtc_state->vrr_params);
> > +
> > + dc_stream_adjust_vmin_vmax(
> > + adev->dm.dc,
> > + acrtc_state->stream,
> > + &acrtc_state->vrr_params.adjust);
> > + spin_unlock_irqrestore(&adev->ddev->event_lock, flags);
> > + }
> > }
> > }
> >
> > @@ -390,6 +407,7 @@ static void dm_crtc_high_irq(void *interrupt_params)
> > struct amdgpu_device *adev = irq_params->adev;
> > struct amdgpu_crtc *acrtc;
> > struct dm_crtc_state *acrtc_state;
> > + unsigned long flags;
> >
> > acrtc = get_crtc_by_otg_inst(adev, irq_params->irq_src - IRQ_TYPE_VBLANK);
> >
> > @@ -412,9 +430,10 @@ static void dm_crtc_high_irq(void *interrupt_params)
> > */
> > amdgpu_dm_crtc_handle_crc_irq(&acrtc->base);
> >
> > - if (acrtc_state->stream &&
> > + if (acrtc_state->stream && adev->family >= AMDGPU_FAMILY_AI &&
> > acrtc_state->vrr_params.supported &&
> > acrtc_state->freesync_config.state == VRR_STATE_ACTIVE_VARIABLE) {
> > + spin_lock_irqsave(&adev->ddev->event_lock, flags);
> > mod_freesync_handle_v_update(
> > adev->dm.freesync_module,
> > acrtc_state->stream,
> > @@ -424,6 +443,7 @@ static void dm_crtc_high_irq(void *interrupt_params)
> > adev->dm.dc,
> > acrtc_state->stream,
> > &acrtc_state->vrr_params.adjust);
> > + spin_unlock_irqrestore(&adev->ddev->event_lock, flags);
> > }
> > }
> > }
> > @@ -4878,8 +4898,10 @@ static void update_freesync_state_on_stream(
> > struct dc_plane_state *surface,
> > u32 flip_timestamp_in_us)
> > {
> > - struct mod_vrr_params vrr_params = new_crtc_state->vrr_params;
> > + struct mod_vrr_params vrr_params;
> > struct dc_info_packet vrr_infopacket = {0};
> > + struct amdgpu_device *adev = dm->adev;
> > + unsigned long flags;
> >
> > if (!new_stream)
> > return;
> > @@ -4892,6 +4914,9 @@ static void update_freesync_state_on_stream(
> > if (!new_stream->timing.h_total || !new_stream->timing.v_total)
> > return;
> >
> > + spin_lock_irqsave(&adev->ddev->event_lock, flags);
> > + vrr_params = new_crtc_state->vrr_params;
> > +
> > if (surface) {
> > mod_freesync_handle_preflip(
> > dm->freesync_module,
> > @@ -4899,6 +4924,12 @@ static void update_freesync_state_on_stream(
> > new_stream,
> > flip_timestamp_in_us,
> > &vrr_params);
> > +
> > + if (adev->family < AMDGPU_FAMILY_AI &&
> > + amdgpu_dm_vrr_active(new_crtc_state)) {
> > + mod_freesync_handle_v_update(dm->freesync_module,
> > + new_stream, &vrr_params);
> > + }
> > }
> >
> > mod_freesync_build_vrr_infopacket(
> > @@ -4930,6 +4961,8 @@ static void update_freesync_state_on_stream(
> > new_crtc_state->base.crtc->base.id,
> > (int)new_crtc_state->base.vrr_enabled,
> > (int)vrr_params.state);
> > +
> > + spin_unlock_irqrestore(&adev->ddev->event_lock, flags);
> > }
> >
> > static void pre_update_freesync_state_on_stream(
> > @@ -4937,8 +4970,10 @@ static void pre_update_freesync_state_on_stream(
> > struct dm_crtc_state *new_crtc_state)
> > {
> > struct dc_stream_state *new_stream = new_crtc_state->stream;
> > - struct mod_vrr_params vrr_params = new_crtc_state->vrr_params;
> > + struct mod_vrr_params vrr_params;
> > struct mod_freesync_config config = new_crtc_state->freesync_config;
> > + struct amdgpu_device *adev = dm->adev;
> > + unsigned long flags;
> >
> > if (!new_stream)
> > return;
> > @@ -4950,6 +4985,9 @@ static void pre_update_freesync_state_on_stream(
> > if (!new_stream->timing.h_total || !new_stream->timing.v_total)
> > return;
> >
> > + spin_lock_irqsave(&adev->ddev->event_lock, flags);
> > + vrr_params = new_crtc_state->vrr_params;
> > +
> > if (new_crtc_state->vrr_supported &&
> > config.min_refresh_in_uhz &&
> > config.max_refresh_in_uhz) {
> > @@ -4970,6 +5008,7 @@ static void pre_update_freesync_state_on_stream(
> > sizeof(vrr_params.adjust)) != 0);
> >
> > new_crtc_state->vrr_params = vrr_params;
> > + spin_unlock_irqrestore(&adev->ddev->event_lock, flags);
> > }
> >
> > static void amdgpu_dm_handle_vrr_transition(struct dm_crtc_state *old_state,
> >
>
More information about the amd-gfx
mailing list