Re: [PATCH v1 net-next] net: stmmac: Add support for MDIO interrupts

[Andrew Lunn]

On Tue, Aug 27, 2019 at 09:45:20AM +0800, Voon Weifeng wrote:
> From: "Chuah, Kim Tatt" <kim.tatt.chuah@xxxxxxxxx>
> 
> DW EQoS v5.xx controllers added capability for interrupt generation
> when MDIO interface is done (GMII Busy bit is cleared).
> This patch adds support for this interrupt on supported HW to avoid
> polling on GMII Busy bit.
> 
> stmmac_mdio_read() & stmmac_mdio_write() will sleep until wake_up() is
> called by the interrupt handler.

Hi Voon

I _think_ there are some order of operation issues here. The mdiobus
is registered in the probe function. As soon as of_mdiobus_register()
is called, the MDIO bus must work. At that point MDIO read/writes can
start to happen.

As far as i can see, the interrupt handler is only requested in
stmmac_open(). So it seems like any MDIO operations after probe, but
before open are going to fail?

Thanks
       Andrew