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[libata] sata_mv: Implement direct FIS transmission via mv_qc_issue_fis().

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This is initially needed to work around NCQ errata,
whereby the READ_LOG_EXT command sometimes fails
when issued in the traditional (sff) fashion.

Portions of this code will likely be reused for
implementation of the target mode feature later on.

Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
This commit is contained in:
Mark Lord 2009-02-25 15:19:20 -05:00 committed by Jeff Garzik
parent 1a660164c2
commit 70f8b79cf3
1 changed files with 116 additions and 0 deletions
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116
drivers/ata/sata_mv.c
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@ -1821,6 +1821,105 @@ static u8 mv_sff_check_status(struct ata_port *ap)
return stat;
}
/**
* mv_send_fis - Send a FIS, using the "Vendor-Unique FIS" register
* @fis: fis to be sent
* @nwords: number of 32-bit words in the fis
*/
static unsigned int mv_send_fis(struct ata_port *ap, u32 *fis, int nwords)
{
void __iomem *port_mmio = mv_ap_base(ap);
u32 ifctl, old_ifctl, ifstat;
int i, timeout = 200, final_word = nwords - 1;
/* Initiate FIS transmission mode */
old_ifctl = readl(port_mmio + SATA_IFCTL_OFS);
ifctl = 0x100 | (old_ifctl & 0xf);
writelfl(ifctl, port_mmio + SATA_IFCTL_OFS);
/* Send all words of the FIS except for the final word */
for (i = 0; i < final_word; ++i)
writel(fis[i], port_mmio + VENDOR_UNIQUE_FIS_OFS);
/* Flag end-of-transmission, and then send the final word */
writelfl(ifctl | 0x200, port_mmio + SATA_IFCTL_OFS);
writelfl(fis[final_word], port_mmio + VENDOR_UNIQUE_FIS_OFS);
/*
* Wait for FIS transmission to complete.
* This typically takes just a single iteration.
*/
do {
ifstat = readl(port_mmio + SATA_IFSTAT_OFS);
} while (!(ifstat & 0x1000) && --timeout);
/* Restore original port configuration */
writelfl(old_ifctl, port_mmio + SATA_IFCTL_OFS);
/* See if it worked */
if ((ifstat & 0x3000) != 0x1000) {
ata_port_printk(ap, KERN_WARNING,
"%s transmission error, ifstat=%08x\n",
__func__, ifstat);
return AC_ERR_OTHER;
}
return 0;
}
/**
* mv_qc_issue_fis - Issue a command directly as a FIS
* @qc: queued command to start
*
* Note that the ATA shadow registers are not updated
* after command issue, so the device will appear "READY"
* if polled, even while it is BUSY processing the command.
*
* So we use a status hook to fake ATA_BUSY until the drive changes state.
*
* Note: we don't get updated shadow regs on *completion*
* of non-data commands. So avoid sending them via this function,
* as they will appear to have completed immediately.
*
* GEN_IIE has special registers that we could get the result tf from,
* but earlier chipsets do not. For now, we ignore those registers.
*/
static unsigned int mv_qc_issue_fis(struct ata_queued_cmd *qc)
{
struct ata_port *ap = qc->ap;
struct mv_port_priv *pp = ap->private_data;
struct ata_link *link = qc->dev->link;
u32 fis[5];
int err = 0;
ata_tf_to_fis(&qc->tf, link->pmp, 1, (void *)fis);
err = mv_send_fis(ap, fis, sizeof(fis) / sizeof(fis[0]));
if (err)
return err;
switch (qc->tf.protocol) {
case ATAPI_PROT_PIO:
pp->pp_flags |= MV_PP_FLAG_FAKE_ATA_BUSY;
/* fall through */
case ATAPI_PROT_NODATA:
ap->hsm_task_state = HSM_ST_FIRST;
break;
case ATA_PROT_PIO:
pp->pp_flags |= MV_PP_FLAG_FAKE_ATA_BUSY;
if (qc->tf.flags & ATA_TFLAG_WRITE)
ap->hsm_task_state = HSM_ST_FIRST;
else
ap->hsm_task_state = HSM_ST;
break;
default:
ap->hsm_task_state = HSM_ST_LAST;
break;
}
if (qc->tf.flags & ATA_TFLAG_POLLING)
ata_pio_queue_task(ap, qc, 0);
return 0;
}
/**
* mv_qc_issue - Initiate a command to the host
* @qc: queued command to start
@ -1896,6 +1995,23 @@ static unsigned int mv_qc_issue(struct ata_queued_cmd *qc)
mv_stop_edma(ap);
mv_clear_and_enable_port_irqs(ap, mv_ap_base(ap), port_irqs);
mv_pmp_select(ap, qc->dev->link->pmp);
if (qc->tf.command == ATA_CMD_READ_LOG_EXT) {
struct mv_host_priv *hpriv = ap->host->private_data;
/*
* Workaround for 88SX60x1 FEr SATA#25 (part 2).
*
* After any NCQ error, the READ_LOG_EXT command
* from libata-eh *must* use mv_qc_issue_fis().
* Otherwise it might fail, due to chip errata.
*
* Rather than special-case it, we'll just *always*
* use this method here for READ_LOG_EXT, making for
* easier testing.
*/
if (IS_GEN_II(hpriv))
return mv_qc_issue_fis(qc);
}
return ata_sff_qc_issue(qc);
}