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

[Zachary Tahenakos]

Acked-by: Zachary Tahenakos <zachary.tahenakos at canonical.com>

On 5/19/22 6:49 PM, David Thompson wrote:
> BugLink: https://bugs.launchpad.net/bugs/1974246
>
> This patch increases the polling rate used by the
> mlxbf_gige driver on the MDIO bus.  The previous
> polling rate was every 100us, and the new rate is
> every 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.
>
> Signed-off-by: David Thompson <davthompson at nvidia.com>
> Signed-off-by: Asmaa Mnebhi <asmaa at nvidia.com>
> Link: https://lore.kernel.org/r/20220505162309.20050-1-davthompson@nvidia.com
> Signed-off-by: Jakub Kicinski <kuba at kernel.org>
> ---
>   drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_mdio.c | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_mdio.c b/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_mdio.c
> index e32dd34fdcc0..6c8a4a529645 100644
> --- a/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_mdio.c
> +++ b/drivers/net/ethernet/mellanox/mlxbf_gige/mlxbf_gige_mdio.c
> @@ -105,7 +105,8 @@ static int mlxbf_gige_mdio_read(struct mii_bus *bus, int phy_add, int phy_reg)
>   	writel(cmd, priv->mdio_io + MLXBF_GIGE_MDIO_GW_OFFSET);
>   
>   	ret = readl_poll_timeout_atomic(priv->mdio_io + MLXBF_GIGE_MDIO_GW_OFFSET,
> -					val, !(val & MLXBF_GIGE_MDIO_GW_BUSY_MASK), 100, 1000000);
> +					val, !(val & MLXBF_GIGE_MDIO_GW_BUSY_MASK),
> +					5, 1000000);
>   
>   	if (ret) {
>   		writel(0, priv->mdio_io + MLXBF_GIGE_MDIO_GW_OFFSET);
> @@ -137,7 +138,8 @@ static int mlxbf_gige_mdio_write(struct mii_bus *bus, int phy_add,
>   
>   	/* If the poll timed out, drop the request */
>   	ret = readl_poll_timeout_atomic(priv->mdio_io + MLXBF_GIGE_MDIO_GW_OFFSET,
> -					temp, !(temp & MLXBF_GIGE_MDIO_GW_BUSY_MASK), 100, 1000000);
> +					temp, !(temp & MLXBF_GIGE_MDIO_GW_BUSY_MASK),
> +					5, 1000000);
>   
>   	return ret;
>   }