Re: [PATCH net 3/4] net: bcmgenet: soft reset 40nm EPHYs before MAC init

From: Florian Fainelli
Date: Wed Oct 16 2019 - 23:54:01 EST

On 10/16/2019 4:06 PM, Doug Berger wrote:
> It turns out that the "Workaround for putting the PHY in IDDQ mode"
> used by the internal EPHYs on 40nm Set-Top Box chips when powering
> down puts the interface to the GENET MAC in a state that can cause
> subsequent MAC resets to be incomplete.
> Rather than restore the forced soft reset when powering up internal
> PHYs, this commit moves the invocation of phy_init_hw earlier in
> the MAC initialization sequence to just before the MAC reset in the
> open and resume functions. This allows the interface to be stable
> and allows the MAC resets to be successful.
> The bcmgenet_mii_probe() function is split in two to accommodate
> this. The new function bcmgenet_mii_connect() handles the first
> half of the functionality before the MAC initialization, and the
> bcmgenet_mii_config() function is extended to provide the remaining
> PHY configuration following the MAC initialization.
> Fixes: 484bfa1507bf ("Revert "net: bcmgenet: Software reset EPHY after power on"")
> Signed-off-by: Doug Berger <opendmb@xxxxxxxxx>

Acked-by: Florian Fainelli <f.fainelli@xxxxxxxxx>

We will have to see how difficult it might be to back port towards
stable trees of interest, hopefully not too difficult.