[patch] Only probe for device combinations that fit in map's bankwidth.

[patch] Only probe for device combinations that fit in map's bankwidth.

[David Vrabel]

Hi,

Recent MTD changed how chip probing is done and it now probes for chips 
of all bus widths.  On my board (IXP425 with 16-bit AMD AM29LV128 flash) 
probing for 8-bit wide devices cannot work because 8-bit writes/reads to 
16-bit devices aren't allowed (they cause data aborts). So...

Make genprobe_new_chip() only probe for combinations that fit in the 
map's bankwidth.

Index: linux-2.6-armbe/drivers/mtd/chips/gen_probe.c
===================================================================
--- linux-2.6-armbe.orig/drivers/mtd/chips/gen_probe.c	2004-09-15 
17:06:44.000000000 +0100
+++ linux-2.6-armbe/drivers/mtd/chips/gen_probe.c	2004-09-16 
11:37:15.000000000 +0100
@@ -172,8 +172,9 @@
  		for (type = 0; type < 3; type++) {
  			cfi->device_type = 1<<type;

-			if (cp->probe_chip(map, 0, NULL, cfi))
-				return 1;
+			if (cfi->device_type * cfi->interleave == map_bankwidth(map))
+				if (cp->probe_chip(map, 0, NULL, cfi))
+					return 1;
  		}
  	}
  	return 0;

David Vrabel
-- 
David Vrabel, Design Engineer

Arcom, Clifton Road           Tel: +44 (0)1223 411200 ext. 3233
Cambridge CB1 7EA, UK         Web: http://www.arcom.com/

Re: [patch] Only probe for device combinations that fit in map's bankwidth.

[Josh Boyer]

On Thu, 2004-09-16 at 05:49, David Vrabel wrote:
> Hi,
> 
> Recent MTD changed how chip probing is done and it now probes for chips 
> of all bus widths.  On my board (IXP425 with 16-bit AMD AM29LV128 flash) 
> probing for 8-bit wide devices cannot work because 8-bit writes/reads to 
> 16-bit devices aren't allowed (they cause data aborts). So...
> 
> Make genprobe_new_chip() only probe for combinations that fit in the 
> map's bankwidth.

MTD CVS has this fixed already.  I noticed the same behavior right after
dwmw2 merged with Linus.  Can you try what's there and see if it fixes
your problem?

josh