[PATCH] ahci: add PIOS interim interrupt handling
During multiblock PIO, multiple PIOS interrupts are generated before
qc compltion. Current code prints unnecessary message for such cases.
This is exposed when new EH slows down attached device into PIO mode.
Signed-off-by: Tejun Heo <htejun@gmail.com>
diff --git a/drivers/scsi/ahci.c b/drivers/scsi/ahci.c
index d6894bd..35487e3 100644
--- a/drivers/scsi/ahci.c
+++ b/drivers/scsi/ahci.c
@@ -883,7 +883,18 @@
}
}
- /* spurious interrupt */
+ /* hmmm... a spurious interupt */
+
+ /* ignore interim PIO setup fis interrupts */
+ if (ata_tag_valid(ap->active_tag)) {
+ struct ata_queued_cmd *qc =
+ ata_qc_from_tag(ap, ap->active_tag);
+
+ if (qc && qc->tf.protocol == ATA_PROT_PIO &&
+ (status & PORT_IRQ_PIOS_FIS))
+ return;
+ }
+
if (ata_ratelimit())
ata_port_printk(ap, KERN_INFO, "spurious interrupt "
"(irq_stat 0x%x active_tag %d)\n",