[PATCH] libata-dev: ata_check_atapi_dma() fix for ATA_FLAG_PIO_POLLING LLDDs
ata_check_atapi_dma() fix for LLDDs with the ATA_FLAG_PIO_POLLING flag.
Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index ef0d0dd..61c120d 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -2883,6 +2883,15 @@
if (ap->ops->check_atapi_dma)
rc = ap->ops->check_atapi_dma(qc);
+ /* We don't support polling DMA.
+ * Use PIO if the LLDD handles only interrupts in
+ * the HSM_ST_LAST state and the ATAPI device
+ * generates CDB interrupts.
+ */
+ if ((ap->flags & ATA_FLAG_PIO_POLLING) &&
+ (qc->dev->flags & ATA_DFLAG_CDB_INTR))
+ rc = 1;
+
return rc;
}
/**
@@ -4038,6 +4047,7 @@
break;
case ATA_PROT_ATAPI_DMA:
if (qc->dev->flags & ATA_DFLAG_CDB_INTR)
+ /* see ata_check_atapi_dma() */
BUG();
break;
default: