As we move towards using a shorter, optimized guardband, we need to adjust
how the delayed vblank start is computed.
Use the helper intel_vrr_compute_guardband() to calculate the optimized
guardband. Since this is measured from the vblank end, we shift the
vblank-start accordingly.
Calculate the minimum delay required based on the guardband and apply it
in intel_crtc_vblank_delay() to update crtc_vblank_start.
Additionally, allow vblank delay adjustment during fastset even when
the CRTC state is not inherited, for platforms where vrr timing generator
(and the static guardband) is used. This ensures correct behavior for LRR
scenarios where vtotal changes but the guardband remains static, allowing
seamless mode transitions.
Signed-off-by: Ankit Nautiyal <ankit.k.nauti...@intel.com>
---
drivers/gpu/drm/i915/display/intel_display.c | 58 ++++++++++++++++++--
1 file changed, 53 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_display.c
b/drivers/gpu/drm/i915/display/intel_display.c
index 73aec6d4686a..d0265391d660 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -2422,14 +2422,55 @@ static int intel_crtc_compute_pipe_mode(struct
intel_crtc_state *crtc_state)
return 0;
}
-static int intel_crtc_vblank_delay(const struct intel_crtc_state *crtc_state)
+static
+int intel_crtc_min_guardband_delay(struct intel_atomic_state *state,
+ struct intel_crtc *crtc)
{
- struct intel_display *display = to_intel_display(crtc_state);
+ struct intel_crtc_state *crtc_state =
+ intel_atomic_get_new_crtc_state(state, crtc);
+ const struct drm_display_mode *adjusted_mode =
+ &crtc_state->hw.adjusted_mode;
+ struct drm_connector_state *conn_state;
+ struct drm_connector *drm_connector;
+ int guardband_delay = 0;
+ int vblank_length;
+ int i;
+
+ vblank_length = adjusted_mode->crtc_vblank_end -
+ adjusted_mode->crtc_vblank_start;
+
+ for_each_new_connector_in_state(&state->base,
+ drm_connector,
+ conn_state, i) {
+ int guardband;
+ struct intel_connector *connector;
+
+ if (conn_state->crtc != &crtc->base)
+ continue;
+
+ connector = to_intel_connector(drm_connector);
+ guardband = intel_vrr_compute_guardband(crtc_state,
+ connector);
+ guardband_delay = vblank_length - guardband;
+ }
+
+ return guardband_delay;
+}
+
+static int intel_crtc_vblank_delay(struct intel_atomic_state *state,
+ struct intel_crtc *crtc)
+{
+ struct intel_display *display = to_intel_display(state);
+ struct intel_crtc_state *crtc_state =
+ intel_atomic_get_new_crtc_state(state, crtc);
int vblank_delay = 0;
if (!HAS_DSB(display))
return 0;
+ if (intel_vrr_always_use_vrr_tg(display))
+ vblank_delay = intel_crtc_min_guardband_delay(state, crtc);
+
vblank_delay = max(vblank_delay,
intel_psr_min_vblank_delay(crtc_state));
return vblank_delay;
@@ -2445,7 +2486,7 @@ static int intel_crtc_compute_vblank_delay(struct
intel_atomic_state *state,
&crtc_state->hw.adjusted_mode;
int vblank_delay, max_vblank_delay;
- vblank_delay = intel_crtc_vblank_delay(crtc_state);
+ vblank_delay = intel_crtc_vblank_delay(state, crtc);
max_vblank_delay = adjusted_mode->crtc_vblank_end -
adjusted_mode->crtc_vblank_start - 1;
if (vblank_delay > max_vblank_delay) {
@@ -5162,9 +5203,16 @@ static bool allow_vblank_delay_fastset(const struct
intel_crtc_state *old_crtc_s
* Allow fastboot to fix up vblank delay (handled via LRR
* codepaths), a bit dodgy as the registers aren't
* double buffered but seems to be working more or less...
+ *
+ * Also allow this when the VRR timing generator is always on,
+ * which implies optimized guardband is used. In such cases,
+ * vblank delay may vary even without inherited state, but it's
+ * still safe as VRR guardband is still same.
*/
- return HAS_LRR(display) && old_crtc_state->inherited &&
- !intel_crtc_has_type(old_crtc_state, INTEL_OUTPUT_DSI);
+ return HAS_LRR(display) &&
+ (old_crtc_state->inherited ||
+ intel_vrr_always_use_vrr_tg(display)) &&
+ !intel_crtc_has_type(old_crtc_state, INTEL_OUTPUT_DSI);
}
bool
--
2.45.2
