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, 4 deletions

diff --git a/drivers/ata/sata_promise.c b/drivers/ata/sata_promise.c
index 5356ec00d2b..2c029ea12c5 100644
--- a/drivers/ata/sata_promise.c
+++ b/drivers/ata/sata_promise.c
@@ -984,8 +984,7 @@ static irqreturn_t pdc_interrupt(int irq, void *dev_instance)
 		/* check for a plug or unplug event */
 		ata_no = pdc_port_no_to_ata_no(i, is_sataii_tx4);
 		tmp = hotplug_status & (0x11 << ata_no);
-		if (tmp && ap &&
-		    !(ap->flags & ATA_FLAG_DISABLED)) {
+		if (tmp) {
 			struct ata_eh_info *ehi = &ap->link.eh_info;
 			ata_ehi_clear_desc(ehi);
 			ata_ehi_hotplugged(ehi);
@@ -997,8 +996,7 @@ static irqreturn_t pdc_interrupt(int irq, void *dev_instance)
 
 		/* check for a packet interrupt */
 		tmp = mask & (1 << (i + 1));
-		if (tmp && ap &&
-		    !(ap->flags & ATA_FLAG_DISABLED)) {
+		if (tmp) {
 			struct ata_queued_cmd *qc;
 
 			qc = ata_qc_from_tag(ap, ap->link.active_tag);