libata: ata_dev_disable() should be called from EH context

ata_port_detach() calls ata_dev_disable() with host lock held but
ata_dev_disable() should be called from EH context.  ata_port_detach()
steals EH context by setting ATA_PFLAG_UNLOADAING and flushing EH.
Drop locking around ata_dev_disable() and note that ata_port_detach()
owns EH context at that point.

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

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 99a18cea316ad44ff2bef16622ea9d21424dc427..c316eacbeddd97c7f547e7a691cccce87b5daa5d 100644 (file)
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -7210,18 +7210,14 @@ static void ata_port_detach(struct ata_port *ap)
 
        ata_port_wait_eh(ap);
 
-       /* EH is now guaranteed to see UNLOADING, so no new device
-        * will be attached.  Disable all existing devices.
+       /* EH is now guaranteed to see UNLOADING - EH context belongs
+        * to us.  Disable all existing devices.
         */
-       spin_lock_irqsave(ap->lock, flags);
-
        ata_port_for_each_link(link, ap) {
                ata_link_for_each_dev(dev, link)
                        ata_dev_disable(dev);
        }
 
-       spin_unlock_irqrestore(ap->lock, flags);
-
        /* Final freeze & EH.  All in-flight commands are aborted.  EH
         * will be skipped and retrials will be terminated with bad
         * target.