Implement per-dev xfermask. libata used to determine xfermask
per-port - the fastest mode of the slowest device on the port. This
patch enables per-dev xfermask.
Original patch is from Alan Cox <alan@xxxxxxxxxx>. The following
changes are made by me.
* simplex warning message is added
* fix port-wide PIO mode selection to aovid violating device selection
timing.
Cc: Alan Cox <alan@xxxxxxxxxx>
Signed-off-by: Tejun Heo <htejun@xxxxxxxxx>
---
drivers/scsi/libata-core.c | 49 +++++++++++++++++++-------------------------
1 files changed, 21 insertions(+), 28 deletions(-)
fd045a27aab1d64997f30a97f64e7aac355dd14d
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 1810bb2..7e1f3ee 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -3040,10 +3040,6 @@ static int ata_dma_blacklisted(const str
* known limits including host controller limits, device
* blacklist, etc...
*
- * FIXME: The current implementation limits all transfer modes to
- * the fastest of the lowested device on the port. This is not
- * required on most controllers.
- *
* LOCKING:
* None.
*/
@@ -3054,6 +3050,7 @@ static void ata_dev_xfermask(struct ata_
unsigned long xfer_mask;
int i;
+ /* controller modes available */
xfer_mask = ata_pack_xfermask(ap->pio_mask,
ap->mwdma_mask, ap->udma_mask);
@@ -3063,34 +3060,30 @@ static void ata_dev_xfermask(struct ata_
if (ap->cbl == ATA_CBL_PATA40)
xfer_mask &= ~(0xF8 << ATA_SHIFT_UDMA);
- /* FIXME: Use port-wide xfermask for now */
- for (i = 0; i < ATA_MAX_DEVICES; i++) {
- struct ata_device *d = &ap->device[i];
-
- if (ata_dev_absent(d))
- continue;
-
- if (ata_dev_disabled(d)) {
- /* to avoid violating device selection timing */
- xfer_mask &= ata_pack_xfermask(d->pio_mask,
- UINT_MAX, UINT_MAX);
- continue;
- }
-
- xfer_mask &= ata_pack_xfermask(d->pio_mask,
- d->mwdma_mask, d->udma_mask);
- xfer_mask &= ata_id_xfermask(d->id);
- if (ata_dma_blacklisted(d))
- xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
- }
+ xfer_mask &= ata_pack_xfermask(dev->pio_mask,
+ dev->mwdma_mask, dev->udma_mask);
+ xfer_mask &= ata_id_xfermask(dev->id);
- if (ata_dma_blacklisted(dev))
+ if (ata_dma_blacklisted(dev)) {
+ xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
ata_dev_printk(dev, KERN_WARNING,
"device is on DMA blacklist, disabling DMA\n");
+ }
+
+ if ((hs->flags & ATA_HOST_SIMPLEX) && hs->simplex_claimed) {
+ xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
+ ata_dev_printk(dev, KERN_WARNING, "simplex DMA is claimed by "
+ "other device, disabling DMA\n");
+ }
- if (hs->flags & ATA_HOST_SIMPLEX) {
- if (hs->simplex_claimed)
- xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
+ /* Use the lowest common PIO mode to avoid violating device
+ * selection timing.
+ */
+ for (i = 0; i < ATA_MAX_DEVICES; i++) {
+ struct ata_device *d = &ap->device[i];
+ if (!ata_dev_absent(d))
+ xfer_mask &= ata_pack_xfermask(d->pio_mask,
+ UINT_MAX, UINT_MAX);
}
if (ap->ops->mode_filter)
--
1.3.2
-
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