Re: [REPOST PATCH] sata_promise: use TF interface for polling NODATA commands

From: Mikael Pettersson
Date: Wed Jun 06 2007 - 07:12:11 EST


On Wed, 6 Jun 2007 19:21:22 +0900, Tejun Heo wrote:
> sata_promise uses two different command modes - packet and TF. Packet
> mode is intelligent low-overhead mode while TF is the same old
> taskfile interface. As with other advanced interface (ahci/sil24),
> ATA_TFLAG_POLLING has no effect in packet mode. However, PIO commands
> are issued using TF interface in polling mode, so pdc_interrupt()
> considers interrupts spurious if ATA_TFLAG_POLLING is set.
>
> This is broken for polling NODATA commands because command is issued
> using packet mode but the interrupt handler ignores it due to
> ATA_TFLAG_POLLING. Fix pdc_qc_issue_prot() such that ATA/ATAPI NODATA
> commands are issued using TF interface if ATA_TFLAG_POLLING is set.
>
> This patch fixes detection failure introduced by polling SETXFERMODE.
>
> Signed-off-by: Tejun Heo <htejun@xxxxxxxxx>
> ---
> David, please verify this patch. Mikael, does this look okay? Please
> push this upstream after David and Mikael's ack.

Thanks Tejun.

I totally agree with the analysis and the solution. I considered bouncing
polled commands back to libata, but Tejun beat me to it :-)

Tested successfully with SATA and PATA disks on 20619, 20575, 20775,
and 40718 chips.

Acked-by: Mikael Pettersson <mikpe@xxxxxxxx>

/Mikael

>
> (This repost is identical to the previous posting but it's now on the
> correct thread.)
>
> Thanks.
>
> drivers/ata/sata_promise.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/ata/sata_promise.c b/drivers/ata/sata_promise.c
> index 2b924a6..6dc0b01 100644
> --- a/drivers/ata/sata_promise.c
> +++ b/drivers/ata/sata_promise.c
> @@ -784,9 +784,12 @@ static unsigned int pdc_qc_issue_prot(struct ata_queued_cmd *qc)
> if (qc->dev->flags & ATA_DFLAG_CDB_INTR)
> break;
> /*FALLTHROUGH*/
> + case ATA_PROT_NODATA:
> + if (qc->tf.flags & ATA_TFLAG_POLLING)
> + break;
> + /*FALLTHROUGH*/
> case ATA_PROT_ATAPI_DMA:
> case ATA_PROT_DMA:
> - case ATA_PROT_NODATA:
> pdc_packet_start(qc);
> return 0;
>
> @@ -800,7 +803,7 @@ static unsigned int pdc_qc_issue_prot(struct ata_queued_cmd *qc)
> static void pdc_tf_load_mmio(struct ata_port *ap, const struct ata_taskfile *tf)
> {
> WARN_ON (tf->protocol == ATA_PROT_DMA ||
> - tf->protocol == ATA_PROT_NODATA);
> + tf->protocol == ATA_PROT_ATAPI_DMA);
> ata_tf_load(ap, tf);
> }
>
> @@ -808,7 +811,7 @@ static void pdc_tf_load_mmio(struct ata_port *ap, const struct ata_taskfile *tf)
> static void pdc_exec_command_mmio(struct ata_port *ap, const struct ata_taskfile *tf)
> {
> WARN_ON (tf->protocol == ATA_PROT_DMA ||
> - tf->protocol == ATA_PROT_NODATA);
> + tf->protocol == ATA_PROT_ATAPI_DMA);
> ata_exec_command(ap, tf);
> }
>
>
-
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