Re: [PATCH] ata: implement MODE SELECT command

[Sergei Shtylyov <sshtylyov@mvista.com>]

Hello.

On 07/04/2012 03:13 PM, Paolo Bonzini wrote:

> The cache_type file in sysfs lets users configure the disk cache in
> write-through or write-back modes.  However, ata disks do not support
> writing to the file because they do not implement the MODE SELECT
> command.

> This patch adds a translation from MODE SELECT (for the caching page
> only) to the ATA SET FEATURES command.

> Cc: Jeff Garzik <jgarzik@pobox.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  drivers/ata/libata-scsi.c |  147 +++++++++++++++++++++++++++++++++++++++++++--
>  1 files changed, 142 insertions(+), 5 deletions(-)

> diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
> index 41cde45..e7702d3 100644
> --- a/drivers/ata/libata-scsi.c
> +++ b/drivers/ata/libata-scsi.c
[...]
> +	switch (pg) {
> +	case CACHE_MPAGE:
> +		if (ata_mselect_caching(tf, p, pg_len))
> +			goto invalid_fld;

   Error is in the data, not CDB, so returning "invalied field in CDB" doesn't
make sense...

> +		break;
> +
> +	default:		/* invalid page code */
> +		goto invalid_fld;
> +	}
> +	return 0;
> +
> + invalid_fld:
> +	ata_scsi_set_sense(scmd, ILLEGAL_REQUEST, 0x24, 0x0);
> +	/* "Invalid field in cbd" */

   s/cbd/CDB/

MBR, Sergei