diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c index ef0d0dd90e17..61c120dae74d 100644 --- a/drivers/scsi/libata-core.c +++ b/drivers/scsi/libata-core.c @@ -2883,6 +2883,15 @@ int ata_check_atapi_dma(struct ata_queued_cmd *qc) 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 @@ unsigned int ata_qc_issue_prot(struct ata_queued_cmd *qc) break; case ATA_PROT_ATAPI_DMA: if (qc->dev->flags & ATA_DFLAG_CDB_INTR) + /* see ata_check_atapi_dma() */ BUG(); break; default: