[libata sata_mv] handle lack of hardware nIEN support
Handle errata (it was unintentional on this h/w, whereas its intentional
on others) whereby the nIEN bit in Device Control is ignored, leading to
a situation where a hardware interrupt completes the qc before the
polling code has a chance to.
This will get fixed The Right Way(tm) once Albert Lee's irq-pio
branch is merged, as the more natural PIO method on this hardware is
interrupt-driven.
diff --git a/drivers/scsi/sata_mv.c b/drivers/scsi/sata_mv.c
index ee0634d..ac184e6 100644
--- a/drivers/scsi/sata_mv.c
+++ b/drivers/scsi/sata_mv.c
@@ -1219,6 +1219,10 @@
handled++;
}
+ if (ap &&
+ (ap->flags & (ATA_FLAG_PORT_DISABLED | ATA_FLAG_NOINTR)))
+ continue;
+
err_mask = ac_err_mask(ata_status);
shift = port << 1; /* (port * 2) */
@@ -1237,7 +1241,8 @@
VPRINTK("port %u IRQ found for qc, "
"ata_status 0x%x\n", port,ata_status);
/* mark qc status appropriately */
- ata_qc_complete(qc, err_mask);
+ if (!(qc->tf.ctl & ATA_NIEN))
+ ata_qc_complete(qc, err_mask);
}
}
}