libata: kill ATA_FLAG_DISABLED

ATA_FLAG_DISABLED is only used by drivers which don't use
->error_handler framework and is largely broken.  Its only meaningful
function is to make irq handlers skip processing if the flag is set,
which is largely useless and even harmful as it makes those ports more
likely to cause IRQ storms.

Kill ATA_FLAG_DISABLED and makes the callers disable attached devices
instead.  ata_port_probe() and ata_port_disable() which manipulate the
flag are also killed.

This simplifies condition check in IRQ handlers.  While updating IRQ
handlers, remove ap NULL check as libata guarantees consecutive port
allocation (unoccupied ports are initialized with dummies) and
long-obsolete ATA_QCFLAG_ACTIVE check (checked by ata_qc_from_tag()).

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 2 insertions, 8 deletions

diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index d5dd88d6dea..0e2c972292c 100644
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -1807,9 +1807,6 @@ retry:
 		struct ata_port *ap = host->ports[i];
 		struct ata_queued_cmd *qc;
 
-		if (unlikely(ap->flags & ATA_FLAG_DISABLED))
-			continue;
-
 		qc = ata_qc_from_tag(ap, ap->link.active_tag);
 		if (qc) {
 			if (!(qc->tf.flags & ATA_TFLAG_POLLING))
@@ -1884,11 +1881,8 @@ void ata_sff_lost_interrupt(struct ata_port *ap)
 
 	/* Only one outstanding command per SFF channel */
 	qc = ata_qc_from_tag(ap, ap->link.active_tag);
-	/* Check we have a live one.. */
-	if (qc == NULL ||  !(qc->flags & ATA_QCFLAG_ACTIVE))
-		return;
-	/* We cannot lose an interrupt on a polled command */
-	if (qc->tf.flags & ATA_TFLAG_POLLING)
+	/* We cannot lose an interrupt on a non-existent or polled command */
+	if (!qc || qc->tf.flags & ATA_TFLAG_POLLING)
 		return;
 	/* See if the controller thinks it is still busy - if so the command
 	   isn't a lost IRQ but is still in progress */