libata: remove ATA_FLAG_LOWTAG

sata_sil24 for some reason pukes when tags are allocated round-robin
which helps tag ordered controllers.  To work around the issue,
72dd299d50 ("libata: allow sata_sil24 to opt-out of tag ordered
submission") introduced ATA_FLAG_LOWTAG which tells libata tag
allocation to do lowest-first.

However, with the recent switch to blk-mq tag allocation, the liata
tag allocation code path is no longer used and the workaround is now
implemented in the block layer and selected by setting
scsi_host_template->tag_alloc_policy to BLK_TAG_ALLOC_FIFO.  See
9269e23496 ("libata: make sata_sil24 use fifo tag allocator").

This leaves ATA_FLAG_LOWTAG withoout any actual user.  Remove it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Shaohua Li <shli@fb.com>
Cc: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Tejun Heo 2015-03-24 14:14:18 -04:00
parent db7a657f3c
commit 3a02824396
3 changed files with 2 additions and 6 deletions

View file

@ -4240,10 +4240,7 @@ int ata_sas_allocate_tag(struct ata_port *ap)
unsigned int i, tag;
for (i = 0, tag = ap->sas_last_tag + 1; i < max_queue; i++, tag++) {
if (ap->flags & ATA_FLAG_LOWTAG)
tag = 1;
else
tag = tag < max_queue ? tag : 0;
tag = tag < max_queue ? tag : 0;
/* the last tag is reserved for internal command. */
if (tag == ATA_TAG_INTERNAL)

View file

@ -246,7 +246,7 @@ enum {
/* host flags */
SIL24_COMMON_FLAGS = ATA_FLAG_SATA | ATA_FLAG_PIO_DMA |
ATA_FLAG_NCQ | ATA_FLAG_ACPI_SATA |
ATA_FLAG_AN | ATA_FLAG_PMP | ATA_FLAG_LOWTAG,
ATA_FLAG_AN | ATA_FLAG_PMP,
SIL24_FLAG_PCIX_IRQ_WOC = (1 << 24), /* IRQ loss errata on PCI-X */
IRQ_STAT_4PORTS = 0xf,

View file

@ -231,7 +231,6 @@ enum {
ATA_FLAG_SW_ACTIVITY = (1 << 22), /* driver supports sw activity
* led */
ATA_FLAG_NO_DIPM = (1 << 23), /* host not happy with DIPM */
ATA_FLAG_LOWTAG = (1 << 24), /* host wants lowest available tag */
/* bits 24:31 of ap->flags are reserved for LLD specific flags */