Re: [PATCH 4.19 223/306] net: dsa: bcm_sf2: Turn on PHY to allow successful registration

From: Pavel Machek
Date: Fri Nov 29 2019 - 08:00:29 EST


Hi!

> From: Florian Fainelli <f.fainelli@xxxxxxxxx>
>
> [ Upstream commit c04a17d2a9ccf1eaba1c5a56f83e997540a70556 ]
>
> We are binding to the PHY using the SF2 slave MDIO bus that we create,
> binding involves reading the PHY's MII_PHYSID1/2 which won't be possible
> if the PHY is turned off. Temporarily turn it on/off for the bus probing
> to succeeed. This fixes unbind/bind problems where the port connecting
> to that PHY would be in error since it could not connect to it.
>
> Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
> ---
> drivers/net/dsa/bcm_sf2.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/net/dsa/bcm_sf2.c b/drivers/net/dsa/bcm_sf2.c
> index ca3655d28e00f..17cec68e56b4f 100644
> --- a/drivers/net/dsa/bcm_sf2.c
> +++ b/drivers/net/dsa/bcm_sf2.c
> @@ -1099,12 +1099,16 @@ static int bcm_sf2_sw_probe(struct platform_device *pdev)
> return ret;
> }
>
> + bcm_sf2_gphy_enable_set(priv->dev->ds, true);
> +
> ret = bcm_sf2_mdio_register(ds);
> if (ret) {
> pr_err("failed to register MDIO bus\n");
> return ret;
> }
>
> + bcm_sf2_gphy_enable_set(priv->dev->ds, false);
> +

This fails to turn off the PHY in the error case. Reordering like this
should fix it:

ret = bcm_sf2_mdio_register(ds);
+ bcm_sf2_gphy_enable_set(priv->dev->ds, false);
if (ret) {
pr_err("failed to register MDIO bus\n");
return ret;
}

Best regards,
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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