libata: clear dev->ering in smarter way
dev->ering used to be cleared together with the rest of ata_device in
ata_dev_init() which is called whenever a probing event occurs.
dev->ering is about to be used to track probing failures so it needs
to remain persistent over multiple porbing events. This patch
achieves this by doing the following.
* Instead of CLEAR_OFFSET, define CLEAR_BEGIN and CLEAR_END and only
clear between BEGIN and END. ering is moved after END. The split
of persistent area is to allow hotter items remain at the head.
* ering is explicitly cleared on ata_dev_disable() and when device
attach succeeds. So, ering is persistent throug a device's life
time (unless explicitly cleared of course) and also through periods
inbetween disablement of an attached device and successful detection
of the next one.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index aafe82b..90092c1 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -1194,6 +1194,11 @@
ata_acpi_on_disable(dev);
ata_down_xfermask_limit(dev, ATA_DNXFER_FORCE_PIO0 | ATA_DNXFER_QUIET);
dev->class++;
+
+ /* From now till the next successful probe, ering is used to
+ * track probe failures. Clear accumulated device error info.
+ */
+ ata_ering_clear(&dev->ering);
}
/**
@@ -2765,6 +2770,8 @@
readid_flags, dev->id);
switch (rc) {
case 0:
+ /* clear error info accumulated during probe */
+ ata_ering_clear(&dev->ering);
new_mask |= 1 << dev->devno;
break;
case -ENOENT: