[SRU][F:linux-bluefield][PATCH v1 0/1] mlxbf_gige: increase MDIO polling rate to 5us

[David Thompson]

BugLink: https://bugs.launchpad.net/bugs/1974246

SRU Justification:

[Impact]

There is MDIO logic within the mlxbf_gige driver that currently
polls for completed transactions every 100us. This has been
reviewed and tested in the lab and found to be inefficient.

[Fix]

The fix is to modify the driver logic to increase the MDIO
polling rate to 5us. With this change the amount of
time spent waiting for the MDIO BUSY signal to de-assert
drops from ~100us to ~27us for each operation.

[Test Case]

The driver should function as before, specifically:
* driver probes successfully
* oob_net0 link comes up, as seen with "ifconfig -a"
* reset and power cycle testing toggle PHY hardware,
  and oob_net0 link still comes up

[Regression Potential]

This change affects all MDIO transactions to the board-level
PHY device, and as such, could cause a regression with PHY
communications. However, this change has been heavily tested.

David Thompson (1):
  mlxbf_gige: increase MDIO polling rate to 5us

 drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_mdio.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

-- 
2.30.1