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authorTejun Heo <tj@kernel.org>2008-06-16 23:36:26 -0400
committerJeff Garzik <jgarzik@redhat.com>2008-06-18 20:27:49 -0400
commit5895ef9a5b746e7cc9ebda50c87fbd11562da0a4 (patch)
tree264ed72edfef60f11260f3227523334b1e1aca80 /drivers/ata
parentd799e083a80b220f3681d7790f11e77d1704022b (diff)
libata: don't check whether to use DMA or not for no data commands
There's no reason to check whether to use DMA or not for no data commands. Don't do it. While at it, make local variable using_pio in atapi_xlat() set iff ATAPI_PROT_PIO is going to be used and rename ata_check_atapi_dma() to atapi_check_dma() for consistency. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Diffstat (limited to 'drivers/ata')
-rw-r--r--drivers/ata/libata-core.c4
-rw-r--r--drivers/ata/libata-scsi.c16
-rw-r--r--drivers/ata/libata.h2
3 files changed, 10 insertions, 12 deletions
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index cc816ca623d3..303fc0d2b978 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -4297,7 +4297,7 @@ void ata_sg_clean(struct ata_queued_cmd *qc)
4297} 4297}
4298 4298
4299/** 4299/**
4300 * ata_check_atapi_dma - Check whether ATAPI DMA can be supported 4300 * atapi_check_dma - Check whether ATAPI DMA can be supported
4301 * @qc: Metadata associated with taskfile to check 4301 * @qc: Metadata associated with taskfile to check
4302 * 4302 *
4303 * Allow low-level driver to filter ATA PACKET commands, returning 4303 * Allow low-level driver to filter ATA PACKET commands, returning
@@ -4310,7 +4310,7 @@ void ata_sg_clean(struct ata_queued_cmd *qc)
4310 * RETURNS: 0 when ATAPI DMA can be used 4310 * RETURNS: 0 when ATAPI DMA can be used
4311 * nonzero otherwise 4311 * nonzero otherwise
4312 */ 4312 */
4313int ata_check_atapi_dma(struct ata_queued_cmd *qc) 4313int atapi_check_dma(struct ata_queued_cmd *qc)
4314{ 4314{
4315 struct ata_port *ap = qc->ap; 4315 struct ata_port *ap = qc->ap;
4316 4316
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 2e6e1622dc6d..57a43649a461 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -2343,8 +2343,8 @@ static unsigned int atapi_xlat(struct ata_queued_cmd *qc)
2343{ 2343{
2344 struct scsi_cmnd *scmd = qc->scsicmd; 2344 struct scsi_cmnd *scmd = qc->scsicmd;
2345 struct ata_device *dev = qc->dev; 2345 struct ata_device *dev = qc->dev;
2346 int using_pio = (dev->flags & ATA_DFLAG_PIO);
2347 int nodata = (scmd->sc_data_direction == DMA_NONE); 2346 int nodata = (scmd->sc_data_direction == DMA_NONE);
2347 int using_pio = !nodata && (dev->flags & ATA_DFLAG_PIO);
2348 unsigned int nbytes; 2348 unsigned int nbytes;
2349 2349
2350 memset(qc->cdb, 0, dev->cdb_len); 2350 memset(qc->cdb, 0, dev->cdb_len);
@@ -2362,7 +2362,7 @@ static unsigned int atapi_xlat(struct ata_queued_cmd *qc)
2362 ata_qc_set_pc_nbytes(qc); 2362 ata_qc_set_pc_nbytes(qc);
2363 2363
2364 /* check whether ATAPI DMA is safe */ 2364 /* check whether ATAPI DMA is safe */
2365 if (!using_pio && ata_check_atapi_dma(qc)) 2365 if (!nodata && !using_pio && atapi_check_dma(qc))
2366 using_pio = 1; 2366 using_pio = 1;
2367 2367
2368 /* Some controller variants snoop this value for Packet 2368 /* Some controller variants snoop this value for Packet
@@ -2402,13 +2402,11 @@ static unsigned int atapi_xlat(struct ata_queued_cmd *qc)
2402 qc->tf.lbam = (nbytes & 0xFF); 2402 qc->tf.lbam = (nbytes & 0xFF);
2403 qc->tf.lbah = (nbytes >> 8); 2403 qc->tf.lbah = (nbytes >> 8);
2404 2404
2405 if (using_pio || nodata) { 2405 if (nodata)
2406 /* no data, or PIO data xfer */ 2406 qc->tf.protocol = ATAPI_PROT_NODATA;
2407 if (nodata) 2407 else if (using_pio)
2408 qc->tf.protocol = ATAPI_PROT_NODATA; 2408 qc->tf.protocol = ATAPI_PROT_PIO;
2409 else 2409 else {
2410 qc->tf.protocol = ATAPI_PROT_PIO;
2411 } else {
2412 /* DMA data xfer */ 2410 /* DMA data xfer */
2413 qc->tf.protocol = ATAPI_PROT_DMA; 2411 qc->tf.protocol = ATAPI_PROT_DMA;
2414 qc->tf.feature |= ATAPI_PKT_DMA; 2412 qc->tf.feature |= ATAPI_PKT_DMA;
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index 4514283937ea..1cf803adbc95 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -106,7 +106,7 @@ extern void ata_sg_clean(struct ata_queued_cmd *qc);
106extern void ata_qc_free(struct ata_queued_cmd *qc); 106extern void ata_qc_free(struct ata_queued_cmd *qc);
107extern void ata_qc_issue(struct ata_queued_cmd *qc); 107extern void ata_qc_issue(struct ata_queued_cmd *qc);
108extern void __ata_qc_complete(struct ata_queued_cmd *qc); 108extern void __ata_qc_complete(struct ata_queued_cmd *qc);
109extern int ata_check_atapi_dma(struct ata_queued_cmd *qc); 109extern int atapi_check_dma(struct ata_queued_cmd *qc);
110extern void swap_buf_le16(u16 *buf, unsigned int buf_words); 110extern void swap_buf_le16(u16 *buf, unsigned int buf_words);
111extern void ata_dev_init(struct ata_device *dev); 111extern void ata_dev_init(struct ata_device *dev);
112extern void ata_link_init(struct ata_port *ap, struct ata_link *link, int pmp); 112extern void ata_link_init(struct ata_port *ap, struct ata_link *link, int pmp);