sna: Do not reuse physical cursors for the kernel is broken, harder

commit 154f7e9668bffdf565b6914a3a3e5bdfe17aa1b9
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Fri Apr 18 09:28:02 2014 +0100

    sna: Do not reuse physical cursors for the kernel is broken

was insufficient as it ended up reusing a stale cursor that was still
attached, and so after updating the cursor the second pipe found itself
with a valid cursor. Hey presto, we had a shared physical cursor, once
again demonstrating the buggy kernel.

This time, disable all cursor reuse except for the once currently
attached to the pipe - this should prevent all sharing.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=77351
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 24 insertions, 19 deletions

diff --git a/src/sna/sna_display.c b/src/sna/sna_display.c
index a356e7fa..ab5b5298 100644
--- a/src/sna/sna_display.c
+++ b/src/sna/sna_display.c
@@ -3170,34 +3170,39 @@ static struct sna_cursor *__sna_get_cursor(struct sna *sna, xf86CrtcPtr crtc)
 	       sna->cursor.ref->bits->argb!=NULL));
 
 	rotation = crtc->transform_in_use ? crtc->rotation : RR_Rotate_0;
-	for (cursor = sna->cursor.cursors; cursor; cursor = cursor->next) {
-		if (cursor->serial == sna->cursor.serial && cursor->rotation == rotation && cursor->image) {
-			__DBG(("%s: reusing handle=%d, serial=%d, rotation=%d, size=%d\n",
-			       __FUNCTION__, cursor->handle, cursor->serial, cursor->rotation, cursor->size));
-			assert(cursor->size == sna->cursor.size);
-			return cursor;
-		}
-	}
-
 	size = sna->cursor.size;
-	for (cursor = sna->cursor.cursors; cursor; cursor = cursor->next) {
-		if (cursor->alloc >= 4*size*size && cursor->rotation == rotation) {
-			__DBG(("%s: stealing handle=%d, serial=%d, rotation=%d, alloc=%d\n",
-			       __FUNCTION__, cursor->handle, cursor->serial, cursor->rotation, cursor->alloc));
-			assert(cursor->serial != sna->cursor.serial);
-			break;
+	if (cursor && cursor->alloc < 4*size*size)
+		cursor = NULL;
+
+	if (sna->kgem.gen >= 033) { /* Don't allow phys cursor sharing */
+		for (cursor = sna->cursor.cursors; cursor; cursor = cursor->next) {
+			if (cursor->serial == sna->cursor.serial && cursor->rotation == rotation) {
+				__DBG(("%s: reusing handle=%d, serial=%d, rotation=%d, size=%d\n",
+				       __FUNCTION__, cursor->handle, cursor->serial, cursor->rotation, cursor->size));
+				assert(cursor->size == sna->cursor.size);
+				return cursor;
+			}
 		}
-	}
 
-	if (cursor == NULL) {
 		for (cursor = sna->cursor.cursors; cursor; cursor = cursor->next) {
-			if (cursor->alloc >= 4*size*size && cursor->serial != sna->cursor.serial) {
+			if (cursor->alloc >= 4*size*size && cursor->rotation == rotation) {
 				__DBG(("%s: stealing handle=%d, serial=%d, rotation=%d, alloc=%d\n",
 				       __FUNCTION__, cursor->handle, cursor->serial, cursor->rotation, cursor->alloc));
-				assert(cursor->rotation != rotation);
+				assert(cursor->serial != sna->cursor.serial);
 				break;
 			}
 		}
+
+		if (cursor == NULL) {
+			for (cursor = sna->cursor.cursors; cursor; cursor = cursor->next) {
+				if (cursor->alloc >= 4*size*size && cursor->serial != sna->cursor.serial) {
+					__DBG(("%s: stealing handle=%d, serial=%d, rotation=%d, alloc=%d\n",
+					       __FUNCTION__, cursor->handle, cursor->serial, cursor->rotation, cursor->alloc));
+					assert(cursor->rotation != rotation);
+					break;
+				}
+			}
+		}
 	}
 
 	if (cursor == NULL) {