Jonny Strom's mga_dma.c patch

1 files changed, 10 insertions, 1 deletions

diff --git a/shared/mga_dma.c b/shared/mga_dma.c
index a0ad70e9..3c84de63 100644
--- a/shared/mga_dma.c
+++ b/shared/mga_dma.c
@@ -157,9 +157,18 @@ void mga_do_dma_flush( drm_mga_private_t *dev_priv )
 {
 	drm_mga_primary_buffer_t *primary = &dev_priv->prim;
 	u32 head, tail;
-	DMA_LOCALS;
+	u32 status = 0;
+	int i;
+ 	DMA_LOCALS;
 	DRM_DEBUG( "\n" );
 
+        /* We need to wait so that we can do an safe flush */
+	for ( i = 0 ; i < dev_priv->usec_timeout ; i++ ) {
+		status = MGA_READ( MGA_STATUS ) & MGA_ENGINE_IDLE_MASK;
+		if ( status == MGA_ENDPRDMASTS ) break;
+		udelay( 1 );
+	}
+
 	if ( primary->tail == primary->last_flush ) {
 		DRM_DEBUG( "   bailing out...\n" );
 		return;