[PATCH v1 0/1] net/e1000: limit 2.5G inter-packet gap workaround to I225

[Rajesh Kumar <rajesh3.kumar@intel.com>]

The igc link update path unconditionally widens the transmit
inter-packet gap (TIPG.IPGT 0x08 -> 0x0b, 12 -> 15 byte times)
whenever the link comes up at 2.5 Gb/s.

This is a workaround for an erratum in early I225 steppings, where
a back-to-back I225 receiver can drop packets arriving with an IPG
below 8 bytes. Applying it to every 2.5G-capable device costs about
0.2% of small-frame transmit rate on I226 and fixed I225 steppings,
which do not need it.

This patch gates the workaround on I225 device IDs with revision_id
below E1000_REVISION_2, and restores the default gap at other speeds
so a renegotiated link does not keep the widened value.

The igc driver has since been merged into net/e1000; this series is
based on that layout and uses the shared e1000 base definitions.

Rajesh Kumar (1):
  net/e1000: limit 2.5G inter-packet gap workaround to I225

 drivers/net/intel/e1000/igc_ethdev.c | 39 +++++++++++++++++++++++++---
 1 file changed, 36 insertions(+), 3 deletions(-)

-- 
2.43.0