- one fix to many

[packages/XFree86-Servers.git] / XFree86-Servers-5480mem.patch

--- XFree86-3.3.6/xc/programs/Xserver/hw/xfree86/vga256/drivers/cirrus/cir_driver.c.5480mem	Sat Jan  8 13:26:49 2000
+++ XFree86-3.3.6/xc/programs/Xserver/hw/xfree86/vga256/drivers/cirrus/cir_driver.c	Mon Feb 21 21:53:18 2000
@@ -1553,17 +1553,18 @@
 	  	/* Use the DRAM bandwidth bit and the DRAM bank switching */
 	  	/* bit to figure out the amount of memory. */
 	  	unsigned char SRF;
+	  	unsigned char SR17;
+
 	  	vga256InfoRec.videoRam = 512;
 	  	outb(0x3c4, 0x0f);
 	  	SRF = inb(0x3c5);
+	  	outb(0x3c4, 0x17);
+	  	SR17 = inb(0x3c5);
 	        if (cirrusChip == CLGD5446) {
 	            /*
 	             * The CL-GD5446 has many different DRAM
 	             * configurations.
 	             */
-	            unsigned char SR17;
-	            outb(0x3c4, 0x17);
-	            SR17 = inb(0x3c5);
   	            vga256InfoRec.videoRam = 1024;
 	  	    if ((SRF & 0x18) == 0x18) {
 	  	        /* 64-bit DRAM bus. */
@@ -1617,6 +1618,13 @@
 	  		/* must be twice as much memory installed. */
 	  		/* (4MB on the 5434) */
 	  		vga256InfoRec.videoRam *= 2;
+	  	    if (cirrusChip == CLGD5480 && (SR17 & 0x80))
+		    	/* 5480's with one 2MB chip show up as 1MB
+			   because they have a 32-bit DRAM bus, but
+			   this seems to fix it.  This is experimental
+			   black magic; if it breaks anything for
+			   you, please help find a better trigger... */
+		    	vga256InfoRec.videoRam *= 2;
 	        }
 	  }
 	  else