diff options
Diffstat (limited to 'drivers/ata/libata-eh.c')
| -rw-r--r-- | drivers/ata/libata-eh.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c index 3b303d4ae37a..16cd676eae1f 100644 --- a/drivers/ata/libata-eh.c +++ b/drivers/ata/libata-eh.c @@ -1542,8 +1542,15 @@ unsigned int atapi_eh_request_sense(struct ata_device *dev, tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE; tf.command = ATA_CMD_PACKET; - /* is it pointless to prefer PIO for "safety reasons"? */ - if (ap->flags & ATA_FLAG_PIO_DMA) { + /* + * Do not use DMA if the connected device only supports PIO, even if the + * port prefers PIO commands via DMA. + * + * Ideally, we should call atapi_check_dma() to check if it is safe for + * the LLD to use DMA for REQUEST_SENSE, but we don't have a qc. + * Since we can't check the command, perhaps we should only use pio? + */ + if ((ap->flags & ATA_FLAG_PIO_DMA) && !(dev->flags & ATA_DFLAG_PIO)) { tf.protocol = ATAPI_PROT_DMA; tf.feature |= ATAPI_PKT_DMA; } else { |