drm: apple: Force modeset when VRR is toggled

DCP requires a "modeset" to trigger the upload of the SDP
to the display. On some monitors, this is instant. On others,
this seems to take as long as a real modeset. Given that in
either case we still blank the display, let's just force a
full modeset when VRR is toggled on or off.

Signed-off-by: James Calligeros <[email protected]>

Author: chadmed

drivers/gpu/drm/apple/dcp-internal.h

@@ -186,6 +186,7 @@ struct apple_dcp {
 	bool during_modeset;
 	bool valid_mode;
 	bool use_timestamps;
+	bool vrr_enabled;
 	struct dcp_set_digital_out_mode_req mode;
 
 	/* completion for active turning true */

drivers/gpu/drm/apple/dcp.c

@@ -361,6 +361,10 @@ int dcp_crtc_atomic_check(struct drm_crtc *crtc, struct drm_atomic_state *state)
 		return -EINVAL;
 	}
 
+	if (dcp->vrr_enabled != crtc_state->vrr_enabled) {
+		crtc_state->mode_changed = true;
+	}
+
 	return 0;
 }
 

drivers/gpu/drm/apple/iomfb_template.c

@@ -1263,7 +1263,7 @@ int DCP_FW_NAME(iomfb_modeset)(struct apple_dcp *dcp,
 	dcp->during_modeset = true;
 
 	if (mode->vrr)
-		dcp_set_adaptive_sync(dcp, mode->min_vrr, cookie);
+		dcp_set_adaptive_sync(dcp, crtc_state->vrr_enabled ? mode->min_vrr : 0, cookie);
 	else
 		dcp_set_digital_out_mode(dcp, false, &dcp->mode,
 					 complete_set_digital_out_mode, cookie);
@@ -1294,6 +1294,7 @@ int DCP_FW_NAME(iomfb_modeset)(struct apple_dcp *dcp,
 			jiffies_to_msecs(ret));
 	}
 	dcp->valid_mode = true;
+	dcp->vrr_enabled = crtc_state->vrr_enabled;
 
 	return 0;
 }