drm/nv50: send evo "update" command after each disconnect

It turns out that the display engine signals an interrupt for disconnects
too.  In order to make it easier to process the display interrupts
correctly, we want to ensure we only get one operation per interrupt
sequence - this is what this commit achieves.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nv50_crtc.c

@@ -449,7 +449,6 @@ nv50_crtc_prepare(struct drm_crtc *crtc)
 static void
 nv50_crtc_commit(struct drm_crtc *crtc)
 {
-	struct drm_crtc *crtc2;
 	struct drm_device *dev = crtc->dev;
 	struct drm_nouveau_private *dev_priv = dev->dev_private;
 	struct nouveau_channel *evo = dev_priv->evo;
@@ -460,20 +459,14 @@ nv50_crtc_commit(struct drm_crtc *crtc)
 
 	nv50_crtc_blank(nv_crtc, false);
 
-	/* Explicitly blank all unused crtc's. */
-	list_for_each_entry(crtc2, &dev->mode_config.crtc_list, head) {
-		if (!drm_helper_crtc_in_use(crtc2))
-			nv50_crtc_blank(nouveau_crtc(crtc2), true);
-	}
-
 	ret = RING_SPACE(evo, 2);
 	if (ret) {
 		NV_ERROR(dev, "no space while committing crtc\n");
 		return;
 	}
 	BEGIN_RING(evo, 0, NV50_EVO_UPDATE, 1);
-	OUT_RING(evo, 0);
-	FIRE_RING(evo);
+	OUT_RING  (evo, 0);
+	FIRE_RING (evo);
 }
 
 static bool

drivers/gpu/drm/nouveau/nv50_dac.c

@@ -47,16 +47,19 @@ nv50_dac_disconnect(struct drm_encoder *encoder)
 
 	if (!nv_encoder->crtc)
 		return;
+	nv50_crtc_blank(nouveau_crtc(nv_encoder->crtc), true);
 
 	NV_DEBUG_KMS(dev, "Disconnecting DAC %d\n", nv_encoder->or);
 
-	ret = RING_SPACE(evo, 2);
+	ret = RING_SPACE(evo, 4);
 	if (ret) {
 		NV_ERROR(dev, "no space while disconnecting DAC\n");
 		return;
 	}
 	BEGIN_RING(evo, 0, NV50_EVO_DAC(nv_encoder->or, MODE_CTRL), 1);
-	OUT_RING(evo, 0);
+	OUT_RING  (evo, 0);
+	BEGIN_RING(evo, 0, NV50_EVO_UPDATE, 1);
+	OUT_RING  (evo, 0);
 
 	nv_encoder->crtc = NULL;
 }

drivers/gpu/drm/nouveau/nv50_sor.c

@@ -47,16 +47,19 @@ nv50_sor_disconnect(struct drm_encoder *encoder)
 
 	if (!nv_encoder->crtc)
 		return;
+	nv50_crtc_blank(nouveau_crtc(nv_encoder->crtc), true);
 
 	NV_DEBUG_KMS(dev, "Disconnecting SOR %d\n", nv_encoder->or);
 
-	ret = RING_SPACE(evo, 2);
+	ret = RING_SPACE(evo, 4);
 	if (ret) {
 		NV_ERROR(dev, "no space while disconnecting SOR\n");
 		return;
 	}
 	BEGIN_RING(evo, 0, NV50_EVO_SOR(nv_encoder->or, MODE_CTRL), 1);
-	OUT_RING(evo, 0);
+	OUT_RING  (evo, 0);
+	BEGIN_RING(evo, 0, NV50_EVO_UPDATE, 1);
+	OUT_RING  (evo, 0);
 
 	nv_encoder->crtc = NULL;
 	nv_encoder->last_dpms = DRM_MODE_DPMS_OFF;