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

[Zachary Tahenakos]

Applied to f:bluefield.

Thanks,

Zack

On 5/19/22 6:49 PM, David Thompson wrote:
> 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(-)
>