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Commit 4658f79b authored by Tejun Heo's avatar Tejun Heo Committed by Jeff Garzik
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[PATCH] ahci: add softreset 



Now that libata is smart enought to handle both soft and hard resets,
add softreset method.

Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent f0c8bbfa

drivers/scsi/ahci.c

+134 −1
Original line number Diff line number Diff line
@@ -513,6 +513,138 @@ static void ahci_fill_cmd_slot(struct ahci_port_priv *pp, u32 opts) 
	pp->cmd_slot[0].tbl_addr_hi = cpu_to_le32((pp->cmd_tbl_dma >> 16) >> 16);

}



static int ahci_poll_register(void __iomem *reg, u32 mask, u32 val,

			      unsigned long interval_msec,

			      unsigned long timeout_msec)

{

	unsigned long timeout;

	u32 tmp;



	timeout = jiffies + (timeout_msec * HZ) / 1000;

	do {

		tmp = readl(reg);

		if ((tmp & mask) == val)

			return 0;

		msleep(interval_msec);

	} while (time_before(jiffies, timeout));



	return -1;

}



static int ahci_softreset(struct ata_port *ap, int verbose, unsigned int *class)

{

	struct ahci_host_priv *hpriv = ap->host_set->private_data;

	struct ahci_port_priv *pp = ap->private_data;

	void __iomem *mmio = ap->host_set->mmio_base;

	void __iomem *port_mmio = ahci_port_base(mmio, ap->port_no);

	const u32 cmd_fis_len = 5; /* five dwords */

	const char *reason = NULL;

	struct ata_taskfile tf;

	u8 *fis;

	int rc;



	DPRINTK("ENTER\n");



	/* prepare for SRST (AHCI-1.1 10.4.1) */

	rc = ahci_stop_engine(ap);

	if (rc) {

		reason = "failed to stop engine";

		goto fail_restart;

	}



	/* check BUSY/DRQ, perform Command List Override if necessary */

	ahci_tf_read(ap, &tf);

	if (tf.command & (ATA_BUSY | ATA_DRQ)) {

		u32 tmp;



		if (!(hpriv->cap & HOST_CAP_CLO)) {

			rc = -EIO;

			reason = "port busy but no CLO";

			goto fail_restart;

		}



		tmp = readl(port_mmio + PORT_CMD);

		tmp |= PORT_CMD_CLO;

		writel(tmp, port_mmio + PORT_CMD);

		readl(port_mmio + PORT_CMD); /* flush */



		if (ahci_poll_register(port_mmio + PORT_CMD, PORT_CMD_CLO, 0x0,

				       1, 500)) {

			rc = -EIO;

			reason = "CLO failed";

			goto fail_restart;

		}

	}



	/* restart engine */

	ahci_start_engine(ap);



	ata_tf_init(ap, &tf, 0);

	fis = pp->cmd_tbl;



	/* issue the first D2H Register FIS */

	ahci_fill_cmd_slot(pp, cmd_fis_len | AHCI_CMD_RESET | AHCI_CMD_CLR_BUSY);



	tf.ctl |= ATA_SRST;

	ata_tf_to_fis(&tf, fis, 0);

	fis[1] &= ~(1 << 7);	/* turn off Command FIS bit */



	writel(1, port_mmio + PORT_CMD_ISSUE);

	readl(port_mmio + PORT_CMD_ISSUE);	/* flush */



	if (ahci_poll_register(port_mmio + PORT_CMD_ISSUE, 0x1, 0x0, 1, 500)) {

		rc = -EIO;

		reason = "1st FIS failed";

		goto fail;

	}



	/* spec says at least 5us, but be generous and sleep for 1ms */

	msleep(1);



	/* issue the second D2H Register FIS */

	ahci_fill_cmd_slot(pp, cmd_fis_len);



	tf.ctl &= ~ATA_SRST;

	ata_tf_to_fis(&tf, fis, 0);

	fis[1] &= ~(1 << 7);	/* turn off Command FIS bit */



	writel(1, port_mmio + PORT_CMD_ISSUE);

	readl(port_mmio + PORT_CMD_ISSUE);	/* flush */



	/* spec mandates ">= 2ms" before checking status.

	 * We wait 150ms, because that was the magic delay used for

	 * ATAPI devices in Hale Landis's ATADRVR, for the period of time

	 * between when the ATA command register is written, and then

	 * status is checked.  Because waiting for "a while" before

	 * checking status is fine, post SRST, we perform this magic

	 * delay here as well.

	 */

	msleep(150);



	*class = ATA_DEV_NONE;

	if (sata_dev_present(ap)) {

		if (ata_busy_sleep(ap, ATA_TMOUT_BOOT_QUICK, ATA_TMOUT_BOOT)) {

			rc = -EIO;

			reason = "device not ready";

			goto fail;

		}

		*class = ahci_dev_classify(ap);

	}



	DPRINTK("EXIT, class=%u\n", *class);

	return 0;



 fail_restart:

	ahci_start_engine(ap);

 fail:

	if (verbose)

		printk(KERN_ERR "ata%u: softreset failed (%s)\n",

		       ap->id, reason);

	else

		DPRINTK("EXIT, rc=%d reason=\"%s\"\n", rc, reason);

	return rc;

}



static int ahci_hardreset(struct ata_port *ap, int verbose, unsigned int *class)

{

	int rc;
@@ -553,7 +685,8 @@ static void ahci_postreset(struct ata_port *ap, unsigned int *class) 


static int ahci_probe_reset(struct ata_port *ap, unsigned int *classes)

{

	return ata_drive_probe_reset(ap, NULL, NULL, ahci_hardreset,

	return ata_drive_probe_reset(ap, ata_std_probeinit,

				     ahci_softreset, ahci_hardreset,

				     ahci_postreset, classes);

}