libata: remove ATA_FLAG_LOWTAG (3a028243) · Commits · 戴 / test

sata_sil24 for some reason pukes when tags are allocated round-robin which helps tag ordered controllers. To work around the issue, ("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 ("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>

drivers/ata/libata-scsi.c

+1 −4

Original line number	Diff line number	Diff line
		@@ -4240,9 +4240,6 @@ 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;

		/* the last tag is reserved for internal command. */

drivers/ata/sata_sil24.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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,

include/linux/libata.h

+0 −1

Original line number	Diff line number	Diff line
		@@ -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 */

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