[PATCH] MTD NAND: Fix ECC errors in au1550nd.c

[Thomas Gleixner]

On Tue, 2005-10-04 at 15:53 +0400, Vitaly Bordug wrote:
> > 
> Actually, yes, a sort of. The issue was in some bytes lost during read 
> cycles (ECC errors reported) when PCMCIA (board AMD Alchemy 1550) is 
> active. This does not take place when 4 CS drives  happen - as shown on 
> the timing diagram - e.g.
> cs: \__/\__/\__/\__/\_<CS low>______ [works fine]
>                      ^
> 	    asserted by SoC controller
> unchanged code:
> cs:\______________/\_[PCMCIA driver steals bytes ]...
> 	           ^
> 	    asserted by SoC controller

Right. Thats a known problem with those FLASH types. You have to hold CS
low until the busy pin goes high.

Hmm, you have to protect against interrupts during this time I guess ?
If not you can use the existing controller lock implementation to
protect against concurrent access.

tglx