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Commit 70f8b79c authored by Mark Lord's avatar Mark Lord Committed by Jeff Garzik
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[libata] sata_mv: Implement direct FIS transmission via mv_qc_issue_fis(). 



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: default avatarMark Lord <mlord@pobox.com>
Signed-off-by: default avatarJeff Garzik <jgarzik@redhat.com>
parent 1a660164

drivers/ata/sata_mv.c

+116 −0
Original line number Diff line number Diff line
@@ -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);

}