From 2db78dd302d26d242d3e8e5c4c5024b6c3ea93c2 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Tue, 2 Oct 2007 13:53:04 -0700 Subject: [PATCH] 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: Alan Cox Signed-off-by: Andrew Morton Signed-off-by: Jeff Garzik --- drivers/ata/libata-scsi.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index df2e05738f..ea53e6a570 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -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; } -- 2.39.5