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

[Tejun Heo <tj@kernel.org>]

Ondrej Zary wrote:
> Hello,
> 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 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 */
> +		memset(&id[ATA_ID_SERNO], 0x20, ATA_ID_SERNO_LEN);
>  	}
>  	return err_mask;
>  }

Looks good to me.  Alan, Jeff?

-- 
tejun