[PATCH 6/6] prime: clean up slave bo properly.

[Dave Airlie]

This is an ABI break, in that we now pass NULL to a function
that hasn't accepted it before.

Alex Goins had a different patch for this but it wasn't symmetrical,
it freed something in a very different place than it allocated it,
this attempts to retain symmetry in the releasing of the backing bo.

Signed-off-by: Dave Airlie <airlied at redhat.com>
---
 dix/pixmap.c                                     | 5 +++++
 hw/xfree86/dri2/dri2.c                           | 1 +
 hw/xfree86/drivers/modesetting/driver.c          | 4 ++++
 hw/xfree86/drivers/modesetting/drmmode_display.c | 6 ++++++
 randr/rrcrtc.c                                   | 2 ++
 5 files changed, 18 insertions(+)

diff --git a/dix/pixmap.c b/dix/pixmap.c
index 11d83fe..270a7d7 100644
--- a/dix/pixmap.c
+++ b/dix/pixmap.c
@@ -140,6 +140,11 @@ PixmapPtr PixmapShareToSlave(PixmapPtr pixmap, ScreenPtr slave)
     ScreenPtr master = pixmap->drawable.pScreen;
     int depth = pixmap->drawable.depth;
 
+    if (!slave) {
+         slave->SetSharedPixmapBacking(spix, NULL);
+         return NULL;
+    }
+
     ret = master->SharePixmapBacking(pixmap, slave, &handle);
     if (ret == FALSE)
         return NULL;
diff --git a/hw/xfree86/dri2/dri2.c b/hw/xfree86/dri2/dri2.c
index d55be19..a961a4e 100644
--- a/hw/xfree86/dri2/dri2.c
+++ b/hw/xfree86/dri2/dri2.c
@@ -859,6 +859,7 @@ DrawablePtr DRI2UpdatePrime(DrawablePtr pDraw, DRI2BufferPtr pDest)
         if (pPriv->prime_slave_pixmap->master_pixmap == mpix)
             return &pPriv->prime_slave_pixmap->drawable;
         else {
+            PixmapShareToSlave(pPriv->prime_slave_pixmap->master_pixmap, NULL);
             (*pPriv->prime_slave_pixmap->master_pixmap->drawable.pScreen->DestroyPixmap)(pPriv->prime_slave_pixmap->master_pixmap);
             (*slave->DestroyPixmap)(pPriv->prime_slave_pixmap);
             pPriv->prime_slave_pixmap = NULL;
diff --git a/hw/xfree86/drivers/modesetting/driver.c b/hw/xfree86/drivers/modesetting/driver.c
index 13c9a10..1735e02 100644
--- a/hw/xfree86/drivers/modesetting/driver.c
+++ b/hw/xfree86/drivers/modesetting/driver.c
@@ -1063,6 +1063,10 @@ msSetSharedPixmapBacking(PixmapPtr ppix, void *fd_handle)
     Bool ret;
     int ihandle = (int) (long) fd_handle;
 
+    if (ihandle == 0)
+        if (!ms->drmmode.reverse_prime_offload_mode)
+           return drmmode_SetSlaveBO(ppix, &ms->drmmode, 0, 0, 0);
+
     if (ms->drmmode.reverse_prime_offload_mode) {
         ret = glamor_back_pixmap_from_fd(ppix, ihandle,
                                          ppix->drawable.width,
diff --git a/hw/xfree86/drivers/modesetting/drmmode_display.c b/hw/xfree86/drivers/modesetting/drmmode_display.c
index 262e015..5cbab07 100644
--- a/hw/xfree86/drivers/modesetting/drmmode_display.c
+++ b/hw/xfree86/drivers/modesetting/drmmode_display.c
@@ -212,6 +212,12 @@ drmmode_SetSlaveBO(PixmapPtr ppix,
 {
     msPixmapPrivPtr ppriv = msGetPixmapPriv(drmmode, ppix);
 
+    if (fd_handle == 0) {
+        dumb_bo_destroy(drmmode->fd, ppriv->backing_bo);
+        ppriv->backing_bo = NULL;
+        return TRUE;
+    }
+
     ppriv->backing_bo =
         dumb_get_bo_from_fd(drmmode->fd, fd_handle, pitch, size);
     if (!ppriv->backing_bo)
diff --git a/randr/rrcrtc.c b/randr/rrcrtc.c
index 566a3db..fe59029 100644
--- a/randr/rrcrtc.c
+++ b/randr/rrcrtc.c
@@ -373,6 +373,8 @@ rrDestroySharedPixmap(RRCrtcPtr crtc, PixmapPtr pPixmap) {
          * Unref the pixmap twice: once for the original reference, and once
          * for the reference implicitly added by PixmapShareToSlave.
          */
+        PixmapShareToSlave(pPixmap->master_pixmap, NULL);
+
         master->DestroyPixmap(pPixmap->master_pixmap);
         master->DestroyPixmap(pPixmap->master_pixmap);
     }
-- 
2.5.5