Commit 8c3c52a8 authored by Tejun Heo's avatar Tejun Heo Committed by Jeff Garzik
Browse files

libata: IDENTIFY backwards for drive side cable detection 



For drive side cable detection to work correctly, drives need to be
identified backwards such that the slave device releases PDIAG- before
the mater drive tries to detect cable type.  ata_bus_probe() was fixed
by commit f31f0cc2 but the new EH path
wasn't fixed.  This patch makes new EH path do IDENTIFY backwards.

ata_dev_configure() for new devices are still performed master first.
This is to keep the detection messages in forward order.

Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent 55a61604

drivers/ata/libata-eh.c

+42 −24
Original line number Diff line number Diff line
@@ -1743,12 +1743,17 @@ static int ata_eh_revalidate_and_attach(struct ata_port *ap, 
{

	struct ata_eh_context *ehc = &ap->eh_context;

	struct ata_device *dev;

	unsigned int new_mask = 0;

	unsigned long flags;

	int i, rc = 0;



	DPRINTK("ENTER\n");



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

	/* For PATA drive side cable detection to work, IDENTIFY must

	 * be done backwards such that PDIAG- is released by the slave

	 * device before the master device is identified.

	 */

	for (i = ATA_MAX_DEVICES - 1; i >= 0; i--) {

		unsigned int action, readid_flags = 0;



		dev = &ap->device[i];
@@ -1760,13 +1765,13 @@ static int ata_eh_revalidate_and_attach(struct ata_port *ap, 
		if (action & ATA_EH_REVALIDATE && ata_dev_ready(dev)) {

			if (ata_port_offline(ap)) {

				rc = -EIO;

				break;

				goto err;

			}



			ata_eh_about_to_do(ap, dev, ATA_EH_REVALIDATE);

			rc = ata_dev_revalidate(dev, readid_flags);

			if (rc)

				break;

				goto err;



			ata_eh_done(ap, dev, ATA_EH_REVALIDATE);
@@ -1784,26 +1789,40 @@ static int ata_eh_revalidate_and_attach(struct ata_port *ap, 


			rc = ata_dev_read_id(dev, &dev->class, readid_flags,

					     dev->id);

			if (rc == 0) {

				ehc->i.flags |= ATA_EHI_PRINTINFO;

				rc = ata_dev_configure(dev);

				ehc->i.flags &= ~ATA_EHI_PRINTINFO;

			} else if (rc == -ENOENT) {

			switch (rc) {

			case 0:

				new_mask |= 1 << i;

				break;

			case -ENOENT:

				/* IDENTIFY was issued to non-existent

				 * device.  No need to reset.  Just

				 * thaw and kill the device.

				 */

				ata_eh_thaw_port(ap);

				dev->class = ATA_DEV_UNKNOWN;

				rc = 0;

			}



			if (rc) {

				dev->class = ATA_DEV_UNKNOWN;

				break;

			default:

				dev->class = ATA_DEV_UNKNOWN;

				goto err;

			}

		}

	}



			if (ata_dev_enabled(dev)) {

	/* Configure new devices forward such that user doesn't see

	 * device detection messages backwards.

	 */

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

		dev = &ap->device[i];



		if (!(new_mask & (1 << i)))

			continue;



		ehc->i.flags |= ATA_EHI_PRINTINFO;

		rc = ata_dev_configure(dev);

		ehc->i.flags &= ~ATA_EHI_PRINTINFO;

		if (rc)

			goto err;



		spin_lock_irqsave(ap->lock, flags);

		ap->pflags |= ATA_PFLAG_SCSI_HOTPLUG;

		spin_unlock_irqrestore(ap->lock, flags);
@@ -1811,13 +1830,12 @@ static int ata_eh_revalidate_and_attach(struct ata_port *ap, 
		/* new device discovered, configure xfermode */

		ehc->i.flags |= ATA_EHI_SETMODE;

	}

		}

	}



	if (rc)

		*r_failed_dev = dev;

	return 0;



	DPRINTK("EXIT\n");

 err:

	*r_failed_dev = dev;

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

	return rc;

}

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