Re: [PATCH] libata: add support for NCQ commands for SG interface

From: Vinayak Kale
Date: Wed Oct 21 2015 - 01:10:21 EST


Hi Tejun,

On Sat, Oct 17, 2015 at 5:18 PM, <vinayak.kale@xxxxxxxxx> wrote:
> From: Vinayak Kale <vinayak.kale@xxxxxxxxxxx>
>
> This patch is needed to make NCQ commands with FPDMA protocol value
> (eg READ/WRITE FPDMA) work over SCSI Generic (SG) interface.
>
> Signed-off-by: Vinayak Kale <vinayak.kale@xxxxxxxxxxx>
> ---
> drivers/ata/libata-scsi.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
> index 0d7f0da..5b0a5ab 100644
> --- a/drivers/ata/libata-scsi.c
> +++ b/drivers/ata/libata-scsi.c
> @@ -2914,12 +2914,14 @@ ata_scsi_map_proto(u8 byte1)
> case 5: /* PIO Data-out */
> return ATA_PROT_PIO;
>
> + case 12: /* FPDMA */
> + return ATA_PROT_NCQ;
> +
> case 0: /* Hard Reset */
> case 1: /* SRST */
> case 8: /* Device Diagnostic */
> case 9: /* Device Reset */
> case 7: /* DMA Queued */
> - case 12: /* FPDMA */
> case 15: /* Return Response Info */
> default: /* Reserved */
> break;
> @@ -2963,7 +2965,7 @@ static unsigned int ata_scsi_pass_thru(struct ata_queued_cmd *qc)
> tf->hob_lbal = cdb[7];
> tf->hob_lbam = cdb[9];
> tf->hob_lbah = cdb[11];
> - tf->flags |= ATA_TFLAG_LBA48;
> + tf->flags |= (ATA_TFLAG_LBA48 | ATA_TFLAG_LBA);
> } else
> tf->flags &= ~ATA_TFLAG_LBA48;
>
> @@ -2992,6 +2994,10 @@ static unsigned int ata_scsi_pass_thru(struct ata_queued_cmd *qc)
> tf->command = cdb[9];
> }
>
> + /* For NCQ commands with FPDMA protocol, copy the tag value */
> + if (tf->protocol == ATA_PROT_NCQ)
> + tf->nsect = qc->tag << 3;
> +
> /* enforce correct master/slave bit */
> tf->device = dev->devno ?
> tf->device | ATA_DEV1 : tf->device & ~ATA_DEV1;
> --
> 1.9.1
>
Any comments on this?

Regards,
Vinayak
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