[PATCH] DRI2: use ConfigNotify to re-allocate buffers if root window changes

[Jesse Barnes]

On Thu, 08 Jul 2010 14:19:23 -0700
Keith Packard <keithp at keithp.com> wrote:

> On Thu, 8 Jul 2010 14:06:01 -0700, Jesse Barnes <jbarnes at virtuousgeek.org> wrote:
> > Ok, back to tracking serials then.
> > 
> > Unfortunately, using the pixmap serial for windows doesn't actually fix
> > this bug.  See below, maybe something is wrong with my
> > DRI2DrawableSerial function.  Using the drawable serial unconditionally
> > lets things work (just like the old patch).
> 
> I'm betting the screen pixmap serial doesn't get bumped when it gets
> resized. Fixing ModifyPixmapHeader might help here?

Ah yep, looks like that was it.  Fixed patch below.  Kristian and
Keith, if it looks ok I'll resubmit with changelog and your reviewed-by
tags.

Thanks,
-- 
Jesse Barnes, Intel Open Source Technology Center

diff --git a/hw/xfree86/dri2/dri2.c b/hw/xfree86/dri2/dri2.c
index f9ba8e7..34f735f 100644
--- a/hw/xfree86/dri2/dri2.c
+++ b/hw/xfree86/dri2/dri2.c
@@ -82,6 +82,7 @@ typedef struct _DRI2Drawable {
     CARD64		 last_swap_msc; /* msc at completion of most recent swap */
     CARD64		 last_swap_ust; /* ust at completion of most recent swap */
     int			 swap_limit; /* for N-buffering */
+    unsigned long	 serialNumber;
 } DRI2DrawableRec, *DRI2DrawablePtr;
 
 typedef struct _DRI2Screen {
@@ -130,6 +131,19 @@ DRI2GetDrawable(DrawablePtr pDraw)
     }
 }
 
+static unsigned long
+DRI2DrawableSerial(DrawablePtr pDraw)
+{
+    ScreenPtr pScreen = pDraw->pScreen;
+    PixmapPtr pPix;
+
+    if (pDraw->type != DRAWABLE_WINDOW)
+	return pDraw->serialNumber;
+
+    pPix = pScreen->GetWindowPixmap((WindowPtr)pDraw);
+    return pPix->drawable.serialNumber;
+}
+
 static DRI2DrawablePtr
 DRI2AllocateDrawable(DrawablePtr pDraw)
 {
@@ -163,6 +177,7 @@ DRI2AllocateDrawable(DrawablePtr pDraw)
     pPriv->last_swap_msc = 0;
     pPriv->last_swap_ust = 0;
     list_init(&pPriv->reference_list);
+    pPriv->serialNumber = DRI2DrawableSerial(pDraw);
 
     if (pDraw->type == DRAWABLE_WINDOW) {
 	pWin = (WindowPtr) pDraw;
@@ -326,6 +341,7 @@ allocate_or_reuse_buffer(DrawablePtr pDraw, DRI2ScreenPtr ds,
 	|| !dimensions_match
 	|| (pPriv->buffers[old_buf]->format != format)) {
 	*buffer = (*ds->CreateBuffer)(pDraw, attachment, format);
+	pPriv->serialNumber = DRI2DrawableSerial(pDraw);
 	return TRUE;
 
     } else {
@@ -384,7 +400,8 @@ do_get_buffers(DrawablePtr pDraw, int *width, int *height,
     }
 
     dimensions_match = (pDraw->width == pPriv->width)
-	&& (pDraw->height == pPriv->height);
+	&& (pDraw->height == pPriv->height)
+	&& (pPriv->serialNumber == DRI2DrawableSerial(pDraw));
 
     buffers = malloc((count + 1) * sizeof(buffers[0]));
 
diff --git a/mi/miscrinit.c b/mi/miscrinit.c
index ea2a0c1..661ecb2 100644
--- a/mi/miscrinit.c
+++ b/mi/miscrinit.c
@@ -76,7 +76,6 @@ miModifyPixmapHeader(PixmapPtr pPixmap, int width, int height, int depth,
 	pPixmap->drawable.depth = depth;
 	pPixmap->drawable.bitsPerPixel = bitsPerPixel;
 	pPixmap->drawable.id = 0;
-	pPixmap->drawable.serialNumber = NEXT_SERIAL_NUMBER;
 	pPixmap->drawable.x = 0;
 	pPixmap->drawable.y = 0;
 	pPixmap->drawable.width = width;
@@ -116,6 +115,7 @@ miModifyPixmapHeader(PixmapPtr pPixmap, int width, int height, int depth,
 	if (pPixData)
 	    pPixmap->devPrivate.ptr = pPixData;
     }
+    pPixmap->drawable.serialNumber = NEXT_SERIAL_NUMBER;
     return TRUE;
 }