dri2: block close-screen until flips complete0.3.0

If CloseScreen happens while we are waiting for a page_flip event, we
need to block the CloseScreen until after the page_flip is processed
to avoid deref'ing the screen ptr after the screen is closed.

3 files changed, 24 insertions, 3 deletions

diff --git a/src/drmmode_display.c b/src/drmmode_display.c
index 371f54e..0dbc01d 100644
--- a/src/drmmode_display.c
+++ b/src/drmmode_display.c
@@ -1295,11 +1295,11 @@ drmmode_uevent_fini(ScrnInfoPtr pScrn)
 static void
 drmmode_wakeup_handler(pointer data, int err, pointer p)
 {
-	ScrnInfoPtr scrn = data;
-	drmmode_ptr drmmode = drmmode_from_scrn(scrn);
+	ScrnInfoPtr pScrn = data;
+	drmmode_ptr drmmode = drmmode_from_scrn(pScrn);
 	fd_set *read_mask = p;
 
-	if (scrn == NULL || err < 0)
+	if (pScrn == NULL || err < 0)
 		return;
 
 	if (FD_ISSET(drmmode->fd, read_mask))
@@ -1307,6 +1307,13 @@ drmmode_wakeup_handler(pointer data, int err, pointer p)
 }
 
 void
+drmmode_wait_for_event(ScrnInfoPtr pScrn)
+{
+	drmmode_ptr drmmode = drmmode_from_scrn(pScrn);
+	drmHandleEvent(drmmode->fd, &event_context);
+}
+
+void
 drmmode_screen_init(ScrnInfoPtr pScrn)
 {
 	drmmode_ptr drmmode = drmmode_from_scrn(pScrn);
diff --git a/src/omap_dri2.c b/src/omap_dri2.c
index db422ef..1ab48e0 100644
--- a/src/omap_dri2.c
+++ b/src/omap_dri2.c
@@ -354,6 +354,7 @@ OMAPDRI2SwapComplete(OMAPDRISwapCmd *cmd)
 {
 	ScreenPtr pScreen = cmd->pScreen;
 	ScrnInfoPtr pScrn = xf86Screens[pScreen->myNum];
+	OMAPPtr pOMAP = OMAPPTR(pScrn);
 	DrawablePtr pDraw = NULL;
 	int status;
 
@@ -375,6 +376,7 @@ OMAPDRI2SwapComplete(OMAPDRISwapCmd *cmd)
 	 */
 	OMAPDRI2DestroyBuffer(pDraw, cmd->pSrcBuffer);
 	OMAPDRI2DestroyBuffer(pDraw, cmd->pDstBuffer);
+	pOMAP->pending_flips--;
 
 	free(cmd);
 }
@@ -399,6 +401,7 @@ OMAPDRI2ScheduleSwap(ClientPtr client, DrawablePtr pDraw,
 {
 	ScreenPtr pScreen = pDraw->pScreen;
 	ScrnInfoPtr pScrn = xf86Screens[pScreen->myNum];
+	OMAPPtr pOMAP = OMAPPTR(pScrn);
 	OMAPDRI2BufferPtr src = OMAPBUF(pSrcBuffer);
 	OMAPDRI2BufferPtr dst = OMAPBUF(pDstBuffer);
 	OMAPDRISwapCmd *cmd = calloc(1, sizeof(*cmd));
@@ -418,6 +421,7 @@ OMAPDRI2ScheduleSwap(ClientPtr client, DrawablePtr pDraw,
 	 */
 	OMAPDRI2ReferenceBuffer(pSrcBuffer);
 	OMAPDRI2ReferenceBuffer(pDstBuffer);
+	pOMAP->pending_flips++;
 
 	if (src->fb_id && dst->fb_id) {
 		DEBUG_MSG("can flip:  %d -> %d", src->fb_id, dst->fb_id);
@@ -506,5 +510,11 @@ OMAPDRI2ScreenInit(ScreenPtr pScreen)
 void
 OMAPDRI2CloseScreen(ScreenPtr pScreen)
 {
+	ScrnInfoPtr pScrn = xf86Screens[pScreen->myNum];
+	OMAPPtr pOMAP = OMAPPTR(pScrn);
+	while (pOMAP->pending_flips > 0) {
+		DEBUG_MSG("waiting..");
+		drmmode_wait_for_event(pScrn);
+	}
 	DRI2CloseScreen(pScreen);
 }
diff --git a/src/omap_driver.h b/src/omap_driver.h
index 028545c..ede45e4 100644
--- a/src/omap_driver.h
+++ b/src/omap_driver.h
@@ -159,6 +159,9 @@ typedef struct _OMAPRec
 
 	XF86VideoAdaptorPtr textureAdaptor;
 
+	/** Flips we are waiting for: */
+	int					pending_flips;
+
 } OMAPRec, *OMAPPtr;
 
 /*
@@ -219,6 +222,7 @@ void drmmode_screen_fini(ScrnInfoPtr pScrn);
 void drmmode_adjust_frame(ScrnInfoPtr pScrn, int x, int y, int flags);
 void drmmode_remove_fb(ScrnInfoPtr pScrn);
 Bool drmmode_page_flip(DrawablePtr draw, uint32_t fb_id, void *priv);
+void drmmode_wait_for_event(ScrnInfoPtr pScrn);
 Bool drmmode_cursor_init(ScreenPtr pScreen);