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-core.c b/drivers/ata/libata-core.c
index d006e5c..564c03c 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -5404,8 +5404,8 @@
dev->horkage = 0;
spin_unlock_irqrestore(ap->lock, flags);
- memset((void *)dev + ATA_DEVICE_CLEAR_OFFSET, 0,
- sizeof(*dev) - ATA_DEVICE_CLEAR_OFFSET);
+ memset((void *)dev + ATA_DEVICE_CLEAR_BEGIN, 0,
+ ATA_DEVICE_CLEAR_END - ATA_DEVICE_CLEAR_BEGIN);
dev->pio_mask = UINT_MAX;
dev->mwdma_mask = UINT_MAX;
dev->udma_mask = UINT_MAX;