Re: [PATCH net v2 7/7] igc: fix link speed advertising

On 26.01.2021 23:10, Tony Nguyen wrote:

From: Corinna Vinschen <redacted>

Link speed advertising in igc has two problems:

- When setting the advertisement via ethtool, the link speed is converted
  to the legacy 32 bit representation for the intel PHY code.
  This inadvertently drops ETHTOOL_LINK_MODE_2500baseT_Full_BIT (being
  beyond bit 31).  As a result, any call to `ethtool -s ...' drops the
  2500Mbit/s link speed from the PHY settings.  Only reloading the driver
  alleviates that problem.

  Fix this by converting the ETHTOOL_LINK_MODE_2500baseT_Full_BIT to the
  Intel PHY ADVERTISE_2500_FULL bit explicitly.

- Rather than checking the actual PHY setting, the .get_link_ksettings
  function always fills link_modes.advertising with all link speeds
  the device is capable of.

  Fix this by checking the PHY autoneg_advertised settings and report
  only the actually advertised speeds up to ethtool.

Fixes: 8c5ad0dae93c ("igc: Add ethtool support")
Signed-off-by: Corinna Vinschen <redacted>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/igc/igc_ethtool.c | 24 +++++++++++++++-----
 1 file changed, 18 insertions(+), 6 deletions(-)

Would switching to phylib be a mid-term option for you?
This could save quite some code and you'd get things like proper 2.5Gbps
handling out of the box. Or is there anything that prevents using phylib?