[PATCH] NAND: Fix NAND ECC errors on AMD Au1550

Sergei Shtylylov sshtylyov at ru.mvista.com
Mon Oct 31 12:55:17 EST 2005


Leif Lindholm wrote:

> On Sun, 2005-10-30 at 23:58 -0800, Pete Popov wrote:
>>It works on the Db1550. I need to run a sanity check on the Db1200. If
>>no one has any objections, I'll commit it in the next couple of days
>>after I check the Db1200.
> Just a comment (forgot to post this last time around):
> At least one of the chips we're using - identified as
> "NAND device: Manufacturer ID: 0xec, Chip ID: 0x76 (Samsung NAND 64MiB 3,3V 8-bit)"
> seems to also need the CS manually asserted during a READID operation.

    Well, the static bus controller seems to hold -CE asserted itself (at
least from what can be seen in the timing diagrams from the Au1550 datasheet)
-- presumably until it has to release it in favor of servicing I/O via another
chip select. That's the point that causes some concern about my patch since I
was unable to assure myself that the chip can tolerate -CS release (and
re-assertion later) during the sector read and not to interrupt the read.
However, the patch proved working, so...

> This made the if-statements ridicilously long, so I added a case
> statement and a variable keeping track of wether or not to force-enable
> CS to the au1550_command function.

    Hm, at what point -CE should be forced low for ID read?

WBR, Sergei

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