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Commit 2db78dd3 authored by Alan Cox's avatar Alan Cox Committed by Jeff Garzik
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libata_scsi: Fix ATAPI transfer lengths 



Some controller variants snoop the ATAPI length value for Packet
transfers to do state machine and FIFO management. Thus we want to
set it properly, even for cases where it is otherwise meaningless.

Signed-off-by: default avatarAlan Cox <alan@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent 681c80b5

drivers/ata/libata-scsi.c

+14 −4
Original line number Diff line number Diff line
@@ -2305,8 +2305,8 @@ static void atapi_request_sense(struct ata_queued_cmd *qc) 
		qc->tf.feature |= ATAPI_PKT_DMA;

	} else {

		qc->tf.protocol = ATA_PROT_ATAPI;

		qc->tf.lbam = (8 * 1024) & 0xff;

		qc->tf.lbah = (8 * 1024) >> 8;

		qc->tf.lbam = SCSI_SENSE_BUFFERSIZE;

		qc->tf.lbah = 0;

	}

	qc->nbytes = SCSI_SENSE_BUFFERSIZE;
@@ -2415,6 +2415,7 @@ static unsigned int atapi_xlat(struct ata_queued_cmd *qc) 
	struct ata_device *dev = qc->dev;

	int using_pio = (dev->flags & ATA_DFLAG_PIO);

	int nodata = (scmd->sc_data_direction == DMA_NONE);

	unsigned int nbytes;



	memset(qc->cdb, 0, dev->cdb_len);

	memcpy(qc->cdb, scmd->cmnd, scmd->cmd_len);
@@ -2434,14 +2435,20 @@ static unsigned int atapi_xlat(struct ata_queued_cmd *qc) 
	if (!using_pio && ata_check_atapi_dma(qc))

		using_pio = 1;



	/* Some controller variants snoop this value for Packet transfers

	   to do state machine and FIFO management. Thus we want to set it

	   properly, and for DMA where it is effectively meaningless */

	nbytes = min(qc->nbytes, (unsigned int)63 * 1024);



	qc->tf.lbam = (nbytes & 0xFF);

	qc->tf.lbah = (nbytes >> 8);



	if (using_pio || nodata) {

		/* no data, or PIO data xfer */

		if (nodata)

			qc->tf.protocol = ATA_PROT_ATAPI_NODATA;

		else

			qc->tf.protocol = ATA_PROT_ATAPI;

		qc->tf.lbam = (8 * 1024) & 0xff;

		qc->tf.lbah = (8 * 1024) >> 8;

	} else {

		/* DMA data xfer */

		qc->tf.protocol = ATA_PROT_ATAPI_DMA;
@@ -2452,6 +2459,9 @@ static unsigned int atapi_xlat(struct ata_queued_cmd *qc) 
			qc->tf.feature |= ATAPI_DMADIR;

	}





	/* FIXME: We need to translate 0x05 READ_BLOCK_LIMITS to a MODE_SENSE

	   as ATAPI tape drives don't get this right otherwise */

	return 0;

}