Why I did it

Some products might experience an occasional IO failure in the communication between CPU and SSD.
Based on some research it could be attributable to some device not handling ATA NCQ (Native Command Queue).

This issue currently affect 4 products:

• DCS-7170-32C*
• DCS-7170-64C
• DCS-7060DX4-32
• DCS-7260CX3-64

How I did it

This change disable NCQ on the affected drive for a small set of products.

How to verify it

When the fix is applied, these 2 patterns can be found in the dmesg.
ata1.00: FORCE: horkage modified (noncq)
NCQ (not used)

Test results using: fio --direct=1 --rw=randrw --bs=64k --ioengine=libaio --iodepth=64 --runtime=120 --numjobs=4

with NCQ (ata1.00: 61865984 sectors, multi 1: LBA48 NCQ (depth 32), AA)

   READ: bw=33.9MiB/s (35.6MB/s), 33.9MiB/s-33.9MiB/s (35.6MB/s-35.6MB/s), io=4073MiB (4270MB), run=120078-120078msec
  WRITE: bw=34.1MiB/s (35.8MB/s), 34.1MiB/s-34.1MiB/s (35.8MB/s-35.8MB/s), io=4100MiB (4300MB), run=120078-120078msec

without NCQ (ata1.00: 61865984 sectors, multi 1: LBA48 NCQ (not used))

   READ: bw=31.7MiB/s (33.3MB/s), 31.7MiB/s-31.7MiB/s (33.3MB/s-33.3MB/s), io=3808MiB (3993MB), run=120083-120083msec
  WRITE: bw=31.9MiB/s (33.4MB/s), 31.9MiB/s-31.9MiB/s (33.4MB/s-33.4MB/s), io=3830MiB (4016MB), run=120083-120083msec

Description for the changelog

Disable ATA NCQ for a few Arista products