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 f31f0cc2f0b7527072d94d02da332d9bb8d7d94c 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: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 361953a..c89664a 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -1743,12 +1743,17 @@
{
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 @@
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);
@@ -1784,40 +1789,53 @@
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;
- }
-
- if (ata_dev_enabled(dev)) {
- spin_lock_irqsave(ap->lock, flags);
- ap->pflags |= ATA_PFLAG_SCSI_HOTPLUG;
- spin_unlock_irqrestore(ap->lock, flags);
-
- /* new device discovered, configure xfermode */
- ehc->i.flags |= ATA_EHI_SETMODE;
+ default:
+ dev->class = ATA_DEV_UNKNOWN;
+ goto err;
}
}
}
- if (rc)
- *r_failed_dev = 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];
- DPRINTK("EXIT\n");
+ 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);
+
+ /* new device discovered, configure xfermode */
+ ehc->i.flags |= ATA_EHI_SETMODE;
+ }
+
+ return 0;
+
+ err:
+ *r_failed_dev = dev;
+ DPRINTK("EXIT rc=%d\n", rc);
return rc;
}