Back in 2.6.17-rc2, a libata module parameter was added for atapi_dmadir. That's nice, but most SATA devices which need it will tell us about it in their IDENTIFY PACKET response, as bit-15 of word-62 of the returned data (as per ATA7, ATA8 specifications). So for those which specify it, we should automatically use the DMADIR bit. Otherwise, disc writing will fail by default on many SATA-ATAPI drives. Signed-off-by: Mark Lord <mlord@xxxxxxxxx> --- old/drivers/ata/libata-scsi.c 2008-02-18 14:45:08.000000000 -0500 +++ linux/drivers/ata/libata-scsi.c 2008-02-18 14:53:02.000000000 -0500 @@ -2543,9 +2543,10 @@ qc->tf.protocol = ATAPI_PROT_DMA; qc->tf.feature |= ATAPI_PKT_DMA; - if (atapi_dmadir && (scmd->sc_data_direction != DMA_TO_DEVICE)) - /* some SATA bridges need us to indicate data xfer direction */ - qc->tf.feature |= ATAPI_DMADIR; + /* some SATA bridges need us to indicate data xfer direction */ + if (atapi_dmadir || (dev->id[62] & 0x8000)) + if (scmd->sc_data_direction != DMA_TO_DEVICE) + qc->tf.feature |= ATAPI_DMADIR; } - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
