Commit 14d2bac1 authored by Tejun Heo's avatar Tejun Heo Committed by Jeff Garzik
Browse files

[PATCH] libata: improve ata_bus_probe() 



Improve ata_bus_probe() such that configuration failures are handled
better.  Each device is given ATA_PROBE_MAX_TRIES chances, but any
non-transient error (revalidation failure with -ENODEV, configuration
failure with -EINVAL...) disables the device directly.  Any IO error
results in SATA PHY speed down and ata_set_mode() failure lowers
transfer mode.  The last try always puts a device into PIO-0.

After each failure, the whole port is reset to make sure that the
controller and all the devices are in a known and stable state.  The
reset also applies SATA SPD configuration if necessary.

Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent cf176e1a

drivers/scsi/libata-core.c

+49 −16
Original line number Diff line number Diff line
@@ -1370,11 +1370,18 @@ static int ata_dev_configure(struct ata_port *ap, struct ata_device *dev, 
static int ata_bus_probe(struct ata_port *ap)

{

	unsigned int classes[ATA_MAX_DEVICES];

	int i, rc, found = 0;

	int tries[ATA_MAX_DEVICES];

	int i, rc, down_xfermask;

	struct ata_device *dev;



	ata_port_probe(ap);



	for (i = 0; i < ATA_MAX_DEVICES; i++)

		tries[i] = ATA_PROBE_MAX_TRIES;



 retry:

	down_xfermask = 0;



	/* reset and determine device classes */

	for (i = 0; i < ATA_MAX_DEVICES; i++)

		classes[i] = ATA_DEV_UNKNOWN;
@@ -1404,21 +1411,23 @@ static int ata_bus_probe(struct ata_port *ap) 
		dev = &ap->device[i];

		dev->class = classes[i];



		if (!ata_dev_enabled(dev))

			continue;



		WARN_ON(dev->id != NULL);

		if (ata_dev_read_id(ap, dev, &dev->class, 1, &dev->id)) {

			dev->class = ATA_DEV_NONE;

			continue;

		if (!tries[i]) {

			ata_down_xfermask_limit(ap, dev, 1);

			ata_dev_disable(ap, dev);

		}



		if (ata_dev_configure(ap, dev, 1)) {

			ata_dev_disable(ap, dev);

		if (!ata_dev_enabled(dev))

			continue;

		}



		found = 1;

		kfree(dev->id);

		dev->id = NULL;

		rc = ata_dev_read_id(ap, dev, &dev->class, 1, &dev->id);

		if (rc)

			goto fail;



		rc = ata_dev_configure(ap, dev, 1);

		if (rc)

			goto fail;

	}



	/* configure transfer mode */
@@ -1427,12 +1436,18 @@ static int ata_bus_probe(struct ata_port *ap) 
		 * return error code and failing device on failure as

		 * ata_set_mode() does.

		 */

		if (found)

		for (i = 0; i < ATA_MAX_DEVICES; i++)

			if (ata_dev_enabled(&ap->device[i])) {

				ap->ops->set_mode(ap);

				break;

			}

		rc = 0;

	} else {

		while (ata_set_mode(ap, &dev))

			ata_dev_disable(ap, dev);

		rc = ata_set_mode(ap, &dev);

		if (rc) {

			down_xfermask = 1;

			goto fail;

		}

	}



	for (i = 0; i < ATA_MAX_DEVICES; i++)
@@ -1443,6 +1458,24 @@ static int ata_bus_probe(struct ata_port *ap) 
	ata_port_disable(ap);

	ap->ops->port_disable(ap);

	return -ENODEV;



 fail:

	switch (rc) {

	case -EINVAL:

	case -ENODEV:

		tries[dev->devno] = 0;

		break;

	case -EIO:

		ata_down_sata_spd_limit(ap);

		/* fall through */

	default:

		tries[dev->devno]--;

		if (down_xfermask &&

		    ata_down_xfermask_limit(ap, dev, tries[dev->devno] == 1))

			tries[dev->devno] = 0;

	}



	goto retry;

}



/**

include/linux/libata.h

+3 −0
Original line number Diff line number Diff line
@@ -211,6 +211,9 @@ enum { 
	/* Masks for port functions */

	ATA_PORT_PRIMARY	= (1 << 0),

	ATA_PORT_SECONDARY	= (1 << 1),



	/* how hard are we gonna try to probe/recover devices */

	ATA_PROBE_MAX_TRIES	= 3,

};



enum hsm_task_states {