Re: [PATCH] [resend] Resume from hibernation fails with pata_it821x RAID volume

[Sergei Shtylyov <sshtylyov@ru.mvista.com>]

Ondrej Zary wrote:

> hibernation didn't work for me since I started to use IT8212 controller. Now I 
> did some debugging (booting with no_console_suspend init=/bin/sh).

> Found that resume fails (2.6.28) with "serial number mismatch 'some 
> garbage' != 'some other garbage'" and "revalidation failed" messages. That's 
> because the controller firmware fills different serial number in the IDENTIFY 
> every boot.

> The patch below fixes the resume simply clearing the serial number. The proper 
> fix would be probably to fill in the serial number of the RAID volume 
> instead.

    I wonder why they just don't put it there (if they indeed have such 
number). If I don't mistake, this is a RAID disk?

> I assume that there must be something like that stored on the drives 
> but I don't know where.

> Fix resume on pata_it821x RAID volume by clearing the serial number in 
> IDENTIFY data, which is otherwise different on each boot.

> Signed-off-by: Ondrej Zary <linux@rainbow-software.org>

> --- linux-2.6.28-orig/drivers/ata/pata_it821x.c	2009-01-02 17:18:36.000000000 
> +0100
> +++ linux/drivers/ata/pata_it821x.c	2009-02-02 17:47:57.000000000 +0100
> @@ -561,6 +561,9 @@
>  		id[83] |= 0x4400;	/* Word 83 is valid and LBA48 */
>  		id[86] |= 0x0400;	/* LBA48 on */
>  		id[ATA_ID_MAJOR_VER] |= 0x1F;
> +		/* Clear the serial number because it's different each boot
> +		   which breaks validation on resume */

    See CodingStyle chapter 8 for the preferred multiline comment style.

> +		memset(&id[ATA_ID_SERNO], 0x20, ATA_ID_SERNO_LEN);

    Why not ' '?

MBR, Sergei