sata_mv: remove bogus nsect restriction

Remove unneeded nsect restriction from GenII NCQ path,
and improve comments to explain why this is not a problem.

Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
This commit is contained in:
Mark Lord 2009-01-19 18:06:28 -05:00 committed by Jeff Garzik
parent cae6edc3b5
commit cd12e1f7a2

View file

@ -349,8 +349,6 @@ enum {
EDMA_HALTCOND_OFS = 0x60, /* GenIIe halt conditions */
GEN_II_NCQ_MAX_SECTORS = 256, /* max sects/io on Gen2 w/NCQ */
/* Host private flags (hp_flags) */
MV_HP_FLAG_MSI = (1 << 0),
MV_HP_ERRATA_50XXB0 = (1 << 1),
@ -1093,20 +1091,12 @@ static void mv6_dev_config(struct ata_device *adev)
*
* Gen-II does not support NCQ over a port multiplier
* (no FIS-based switching).
*
* We don't have hob_nsect when doing NCQ commands on Gen-II.
* See mv_qc_prep() for more info.
*/
if (adev->flags & ATA_DFLAG_NCQ) {
if (sata_pmp_attached(adev->link->ap)) {
adev->flags &= ~ATA_DFLAG_NCQ;
ata_dev_printk(adev, KERN_INFO,
"NCQ disabled for command-based switching\n");
} else if (adev->max_sectors > GEN_II_NCQ_MAX_SECTORS) {
adev->max_sectors = GEN_II_NCQ_MAX_SECTORS;
ata_dev_printk(adev, KERN_INFO,
"max_sectors limited to %u for NCQ\n",
adev->max_sectors);
}
}
}
@ -1444,7 +1434,8 @@ static void mv_qc_prep(struct ata_queued_cmd *qc)
* only 11 bytes...so we must pick and choose required
* registers based on the command. So, we drop feature and
* hob_feature for [RW] DMA commands, but they are needed for
* NCQ. NCQ will drop hob_nsect.
* NCQ. NCQ will drop hob_nsect, which is not needed there
* (nsect is used only for the tag; feat/hob_feat hold true nsect).
*/
switch (tf->command) {
case ATA_CMD_READ: