modesetting: Always tear down scanout pixmap

drmmode_set_scanout_pixmap_(cpu/gpu) would only do teardown if ppix ==
NULL. This meant that if there were consecutive calls to
SetScanoutPixmap(ppix != NULL) without calls to SetScanoutPixmap(ppix ==
NULL) in between, earlier calls would be leaked.  RRReplaceScanoutPixmap()
does this today.

Instead, when setting a scanout pixmap, always do teardown of the existing
scanout pixmap before setting up the new one. Then, if there is no new one
to set up, stop there.

This maintains the previous behavior in all cases except those with
multiple consecutive calls to SetScanoutPixmap(ppix != NULL).

v1: N/A
v2: N/A
v3: N/A
v4: N/A
v5: Initial commit
v6: Rebase onto ToT
v7: Unchanged

Reviewed-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Alex Goins <agoins@nvidia.com>

1 files changed, 20 insertions, 19 deletions

diff --git a/hw/xfree86/drivers/modesetting/drmmode_display.c b/hw/xfree86/drivers/modesetting/drmmode_display.c
index 89c468b34..cce9a3378 100644
--- a/hw/xfree86/drivers/modesetting/drmmode_display.c
+++ b/hw/xfree86/drivers/modesetting/drmmode_display.c
@@ -638,17 +638,18 @@ drmmode_set_scanout_pixmap_gpu(xf86CrtcPtr crtc, PixmapPtr ppix)
     drmmode_ptr drmmode = drmmode_crtc->drmmode;
     int c, total_width = 0, max_height = 0, this_x = 0;
 
-    if (!ppix) {
-        if (drmmode_crtc->prime_pixmap) {
-            PixmapStopDirtyTracking(drmmode_crtc->prime_pixmap, screenpix);
-            if (drmmode->fb_id) {
-                drmModeRmFB(drmmode->fd, drmmode->fb_id);
-                drmmode->fb_id = 0;
-            }
+    if (drmmode_crtc->prime_pixmap) {
+        PixmapStopDirtyTracking(drmmode_crtc->prime_pixmap, screenpix);
+        if (drmmode->fb_id) {
+            drmModeRmFB(drmmode->fd, drmmode->fb_id);
+            drmmode->fb_id = 0;
         }
         drmmode_crtc->prime_pixmap_x = 0;
-        return TRUE;
     }
+
+    if (!ppix)
+        return TRUE;
+
     /* iterate over all the attached crtcs to work out the bounding box */
     for (c = 0; c < xf86_config->num_crtc; c++) {
         xf86CrtcPtr iter = xf86_config->crtc[c];
@@ -689,18 +690,18 @@ drmmode_set_scanout_pixmap_cpu(xf86CrtcPtr crtc, PixmapPtr ppix)
     msPixmapPrivPtr ppriv;
     void *ptr;
 
-    if (!ppix) {
-        if (drmmode_crtc->prime_pixmap) {
-            ppriv = msGetPixmapPriv(drmmode, drmmode_crtc->prime_pixmap);
-            drmModeRmFB(drmmode->fd, ppriv->fb_id);
-            ppriv->fb_id = 0;
-        }
-        if (drmmode_crtc->slave_damage) {
-            DamageUnregister(drmmode_crtc->slave_damage);
-            drmmode_crtc->slave_damage = NULL;
-        }
-        return TRUE;
+    if (drmmode_crtc->prime_pixmap) {
+        ppriv = msGetPixmapPriv(drmmode, drmmode_crtc->prime_pixmap);
+        drmModeRmFB(drmmode->fd, ppriv->fb_id);
+        ppriv->fb_id = 0;
     }
+    if (drmmode_crtc->slave_damage) {
+        DamageUnregister(drmmode_crtc->slave_damage);
+        drmmode_crtc->slave_damage = NULL;
+    }
+
+    if (!ppix)
+        return TRUE;
 
     ppriv = msGetPixmapPriv(drmmode, ppix);
     if (!drmmode_crtc->slave_damage) {