drm/i915/dsb: Use safe window path when VRR TG is used

When the VRR timing generator is always used, the hardware behaves
as VRR-active regardless of crtc_state->vrr.enable.

The DSB paths that depend on the VRR safe window therefore need to follow
the VRR code paths in that case too:
- dsb_chicken(): program the SAFE_WINDOW chicken bits,
- intel_dsb_vblank_evade(): use vmin/vmax vblank starts for the
  wait window,
- intel_dsb_wait_for_delayed_vblank(): wait inside the vmin safe window
  before the scanline-based delayed vblank wait.

Introduce helper pre_commit_use_safe_window() and use it in the three sites

v2: Instead of modifying pre_commit_is_vrr_active() use a new helper and
    use it only in the required places. (Ville).

v3: -Keep using pre_commit_is_vrr_active() for DCB path. (Ville)
    -Add a separate check for fixed RR with VRR TG and use
     fixed mode vblank start there. (Ville)

Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20260617051417.2223526-1-ankit.k.nautiyal@intel.com
This commit is contained in:
Ankit Nautiyal
2026-06-17 10:44:17 +05:30
parent f7140c7cef
commit 4a68c7516c

View File

@@ -210,6 +210,18 @@ static int dsb_scanline_to_hw(struct intel_atomic_state *state,
return (scanline + vtotal - intel_crtc_scanline_offset(crtc_state)) % vtotal;
}
static
bool pre_commit_use_safe_window(struct intel_atomic_state *state,
struct intel_crtc *crtc)
{
struct intel_display *display = to_intel_display(crtc->base.dev);
if (intel_vrr_always_use_vrr_tg(display))
return true;
return pre_commit_is_vrr_active(state, crtc);
}
/*
* Bspec suggests that we should always set DSB_SKIP_WAITS_EN. We have approach
* different from what is explained in Bspec on how flip is considered being
@@ -229,7 +241,7 @@ static u32 dsb_chicken(struct intel_atomic_state *state,
u32 chicken = intel_psr_use_trans_push(new_crtc_state) ?
DSB_SKIP_WAITS_EN : 0;
if (pre_commit_is_vrr_active(state, crtc))
if (pre_commit_use_safe_window(state, crtc))
chicken |= DSB_CTRL_WAIT_SAFE_WINDOW |
DSB_CTRL_NO_WAIT_VBLANK |
DSB_INST_WAIT_SAFE_WINDOW |
@@ -798,6 +810,12 @@ void intel_dsb_vblank_evade(struct intel_atomic_state *state,
end = intel_vrr_vmax_vblank_start(crtc_state);
start = end - vblank_delay - latency;
intel_dsb_wait_scanline_out(state, dsb, start, end);
} else if (pre_commit_use_safe_window(state, crtc)) {
int vblank_delay = crtc_state->set_context_latency;
end = intel_mode_vblank_start(&crtc_state->hw.adjusted_mode);
start = end - vblank_delay - latency;
intel_dsb_wait_scanline_out(state, dsb, start, end);
} else {
int vblank_delay = intel_mode_vblank_delay(&crtc_state->hw.adjusted_mode);
@@ -891,7 +909,7 @@ void intel_dsb_wait_for_delayed_vblank(struct intel_atomic_state *state,
&crtc_state->hw.adjusted_mode;
int wait_scanlines;
if (pre_commit_is_vrr_active(state, crtc)) {
if (pre_commit_use_safe_window(state, crtc)) {
/*
* If the push happened before the vmin decision boundary
* we don't know how far we are from the undelayed vblank.