Re: [PATCH net] net: phy: aquantia: wait for the suspend/resume operations to finish

[Ioana Ciornei <ioana.ciornei@nxp.com>]

On Mon, Sep 05, 2022 at 04:58:33PM +0300, Ioana Ciornei wrote:
> The Aquantia datasheet notes that after issuing a Processor-Intensive
> MDIO operation, like changing the low-power state of the device, the
> driver should wait for the operation to finish before issuing a new MDIO
> command.
> 
> The new aqr107_wait_processor_intensive_op() function is added which can
> be used after these kind of MDIO operations. At the moment, we are only
> adding it at the end of the suspend/resume calls.
> 
> The issue was identified on a board featuring the AQR113C PHY, on
> which commands like 'ip link (..) up / down' issued without any delays
> between them would render the link on the PHY to remain down.
> The issue was easy to reproduce with a one-liner:
>  $ ip link set dev ethX down; ip link set dev ethX up; \
>  ip link set dev ethX down; ip link set dev ethX up;
> 
> Fixes: ac9e81c230eb ("net: phy: aquantia: add suspend / resume callbacks for AQR107 family")
> Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>

I just stumbled upon the phy_read_mmd_poll_timeout() API which takes
care of polling on an MDIO register without having to declare a separate
read function.

I'll send a v2 on this with the change later today or tomorrow.

Ioana