drm/nv04: Fix scanout over the 16MB mark.

Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_hw.h

@@ -415,6 +415,25 @@ nv_fix_nv40_hw_cursor(struct drm_device *dev, int head)
 	NVWriteRAMDAC(dev, head, NV_PRAMDAC_CU_START_POS, curpos);
 }
 
+static inline void
+nv_set_crtc_base(struct drm_device *dev, int head, uint32_t offset)
+{
+	struct drm_nouveau_private *dev_priv = dev->dev_private;
+
+	NVWriteCRTC(dev, head, NV_PCRTC_START, offset);
+
+	if (dev_priv->card_type == NV_04) {
+		/*
+		 * Hilarious, the 24th bit doesn't want to stick to
+		 * PCRTC_START...
+		 */
+		int cre_heb = NVReadVgaCrtc(dev, head, NV_CIO_CRE_HEB__INDEX);
+
+		NVWriteVgaCrtc(dev, head, NV_CIO_CRE_HEB__INDEX,
+			       (cre_heb & ~0x40) | ((offset >> 18) & 0x40));
+	}
+}
+
 static inline void
 nv_show_cursor(struct drm_device *dev, int head, bool show)
 {

drivers/gpu/drm/nouveau/nv04_crtc.c

@@ -831,7 +831,7 @@ nv04_crtc_do_mode_set_base(struct drm_crtc *crtc,
 	/* Update the framebuffer location. */
 	regp->fb_start = nv_crtc->fb.offset & ~3;
 	regp->fb_start += (y * drm_fb->pitch) + (x * drm_fb->bits_per_pixel / 8);
-	NVWriteCRTC(dev, nv_crtc->index, NV_PCRTC_START, regp->fb_start);
+	nv_set_crtc_base(dev, nv_crtc->index, regp->fb_start);
 
 	/* Update the arbitration parameters. */
 	nouveau_calc_arb(dev, crtc->mode.clock, drm_fb->bits_per_pixel,