--- drivers/char/agp/generic.c~	2003-08-08 03:05:06.000000000 +0200
+++ drivers/char/agp/generic.c	2003-08-08 03:05:06.000000000 +0200
@@ -453,9 +453,9 @@
 
 	/* Clear out unwanted bits. */
 	if (*cmd & AGPSTAT3_8X)
-		*cmd = ~(AGPSTAT3_4X | AGPSTAT3_RSVD);
+		*cmd &= ~(AGPSTAT3_4X | AGPSTAT3_RSVD);
 	if (*cmd & AGPSTAT3_4X)
-		*cmd = ~(AGPSTAT3_8X | AGPSTAT3_RSVD);
+		*cmd &= ~(AGPSTAT3_8X | AGPSTAT3_RSVD);
 }
 
 //FIXME: This doesn't smell right.