Commit 37deecb5 authored by Tejun Heo's avatar Tejun Heo
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[PATCH] libata: implement per-dev xfermask 



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@redhat.com>.  The following
changes are made by me.

* simplex warning message is added
* remove disabled device handling code which is never invoked
  (originally for choosing port-wide lowest PIO mode)

Cc: Alan Cox <alan@redhat.com>
Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
parent 6d0500df

drivers/scsi/libata-core.c

+11 −29
Original line number Diff line number Diff line
@@ -3040,10 +3040,6 @@ static int ata_dma_blacklisted(const struct ata_device *dev) 
 *	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.

 */
@@ -3052,8 +3048,8 @@ static void ata_dev_xfermask(struct ata_device *dev) 
	struct ata_port *ap = dev->ap;

	struct ata_host_set *hs = ap->host_set;

	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 +3059,20 @@ static void ata_dev_xfermask(struct ata_device *dev) 
	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;

	xfer_mask &= ata_pack_xfermask(dev->pio_mask,

				       dev->mwdma_mask, dev->udma_mask);

	xfer_mask &= ata_id_xfermask(dev->id);



		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))

	if (ata_dma_blacklisted(dev)) {

		xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);

	}



	if (ata_dma_blacklisted(dev))

		ata_dev_printk(dev, KERN_WARNING,

			       "device is on DMA blacklist, disabling DMA\n");

	}



	if (hs->flags & ATA_HOST_SIMPLEX) {

		if (hs->simplex_claimed)

	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 (ap->ops->mode_filter)

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