diff options
| author | Tejun Heo <htejun@gmail.com> | 2007-12-05 16:43:10 +0900 |
|---|---|---|
| committer | Jeff Garzik <jeff@garzik.org> | 2008-01-23 05:24:14 -0500 |
| commit | f92a26365a72333f418abe82700c6030d4a1a807 (patch) | |
| tree | 73bb3ae684abfabf2d0aecac33af1a3f2112afc4 | |
| parent | 001102d7859be0e7f7b9f2d62b841f2c0f9c2640 (diff) | |
libata: change ATA_QCFLAG_DMAMAP semantics
ATA_QCFLAG_DMAMAP was a bit peculiar in that it got set during qc
initialization and cleared if DMA mapping wasn't necessary. Make it
more straight forward by making the following changes.
* Don't set it during initialization. Set it after DMA is actually
mapped.
* Add BUG_ON() to guarantee that there is data to transfer if DMAMAP
is set. This always holds for the current code. The BUG_ON() is
for docummentation and sanity check.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
| -rw-r--r-- | drivers/ata/libata-core.c | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 76360f0ca20..865428a64de 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -4475,7 +4475,6 @@ void ata_sg_clean(struct ata_queued_cmd *qc) int dir = qc->dma_dir; void *pad_buf = NULL; - WARN_ON(!(qc->flags & ATA_QCFLAG_DMAMAP)); WARN_ON(sg == NULL); VPRINTK("unmapping %u sg elements\n", qc->n_elem); @@ -4762,11 +4761,9 @@ void ata_noop_qc_prep(struct ata_queued_cmd *qc) { } * LOCKING: * spin_lock_irqsave(host lock) */ - void ata_sg_init(struct ata_queued_cmd *qc, struct scatterlist *sg, unsigned int n_elem) { - qc->flags |= ATA_QCFLAG_DMAMAP; qc->__sg = sg; qc->n_elem = n_elem; qc->orig_n_elem = n_elem; @@ -4795,7 +4792,6 @@ static int ata_sg_setup(struct ata_queued_cmd *qc) int n_elem, pre_n_elem, dir, trim_sg = 0; VPRINTK("ENTER, ata%u\n", ap->print_id); - WARN_ON(!(qc->flags & ATA_QCFLAG_DMAMAP)); /* we must lengthen transfers to end on a 32-bit boundary */ qc->pad_len = lsg->length & 3; @@ -4855,6 +4851,7 @@ static int ata_sg_setup(struct ata_queued_cmd *qc) skip_map: qc->n_elem = n_elem; + qc->flags |= ATA_QCFLAG_DMAMAP; return 0; } @@ -5912,12 +5909,15 @@ void ata_qc_issue(struct ata_queued_cmd *qc) qc->flags |= ATA_QCFLAG_ACTIVE; ap->qc_active |= 1 << qc->tag; + /* We guarantee to LLDs that they will have at least one + * non-zero sg if the command is a data command. + */ + BUG_ON(ata_is_data(prot) && (!qc->__sg || !qc->n_elem || !qc->nbytes)); + if (ata_is_dma(prot) || (ata_is_pio(prot) && - (ap->flags & ATA_FLAG_PIO_DMA))) { + (ap->flags & ATA_FLAG_PIO_DMA))) if (ata_sg_setup(qc)) goto sg_err; - } else - qc->flags &= ATA_QCFLAG_DMAMAP; /* if device is sleeping, schedule softreset and abort the link */ if (unlikely(qc->dev->flags & ATA_DFLAG_SLEEPING)) { @@ -5935,7 +5935,6 @@ void ata_qc_issue(struct ata_queued_cmd *qc) return; sg_err: - qc->flags &= ~ATA_QCFLAG_DMAMAP; qc->err_mask |= AC_ERR_SYSTEM; err: ata_qc_complete(qc); |