[PATCH] libata: implement ata_dev_revalidate()

ata_dev_revalidate() re-reads IDENTIFY PAGE of the given device and
makes sure it's the same device as the configured one.  Once it's
verified that it's the same device, @dev is configured according to
newly read IDENTIFY PAGE.  Note that revalidation currently doesn't
invoke transfer mode reconfiguration.

Criteria for 'same device'

* same class (of course)
* same model string
* same serial string
* if ATA, same n_sectors (to catch geometry parameter changes)

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 86a504f0ef06..66dce58f1941 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -485,6 +485,8 @@ extern int ata_std_softreset(struct ata_port *ap, int verbose,
 extern int sata_std_hardreset(struct ata_port *ap, int verbose,
                               unsigned int *class);
 extern void ata_std_postreset(struct ata_port *ap, unsigned int *classes);
+extern int ata_dev_revalidate(struct ata_port *ap, struct ata_device *dev,
+                              int post_reset);
 extern void ata_port_disable(struct ata_port *);
 extern void ata_std_ports(struct ata_ioports *ioaddr);
 #ifdef CONFIG_PCI