RE: [PATCH] net: fec: Fix phy_device lookup for phy_reset_after_clk_enable() [Klartext]

[Christoph Niedermaier <cniedermaier@dh-electronics.com>]

From: Marek Vasut <marex@denx.de>
Sent: Tuesday, October 6, 2020 10:20 PM

> The phy_reset_after_clk_enable() is always called with ndev->phydev,
> however that pointer may be NULL even though the PHY device instance
> already exists and is sufficient to perform the PHY reset.
> 
> If the PHY still is not bound to the MAC, but there is OF PHY node
> and a matching PHY device instance already, use the OF PHY node to
> obtain the PHY device instance, and then use that PHY device instance
> when triggering the PHY reset.
> 
> Fixes: 1b0a83ac04e3 ("net: fec: add phy_reset_after_clk_enable() support")
> Signed-off-by: Marek Vasut <marex@denx.de>
> Cc: Christoph Niedermaier <cniedermaier@dh-electronics.com>
> Cc: David S. Miller <davem@davemloft.net>
> Cc: NXP Linux Team <linux-imx@nxp.com>
> Cc: Richard Leitner <richard.leitner@skidata.com>
> Cc: Shawn Guo <shawnguo@kernel.org>
> ---
>  drivers/net/ethernet/freescale/fec_main.c | 22 ++++++++++++++++++++--
>  1 file changed, 20 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/freescale/fec_main.c
> b/drivers/net/ethernet/freescale/fec_main.c
> index 2d5433301843..5a4b20941aeb 100644
> --- a/drivers/net/ethernet/freescale/fec_main.c
> +++ b/drivers/net/ethernet/freescale/fec_main.c
> @@ -1912,6 +1912,24 @@ static int fec_enet_mdio_write(struct mii_bus *bus,
> int mii_id, int regnum,
>         return ret;
>  }
> 
> +static void fec_enet_phy_reset_after_clk_enable(struct net_device *ndev)
> +{
> +       struct fec_enet_private *fep = netdev_priv(ndev);
> +       struct phy_device *phy_dev = ndev->phydev;
> +
> +       /*
> +        * If the PHY still is not bound to the MAC, but there is
> +        * OF PHY node and a matching PHY device instance already,
> +        * use the OF PHY node to obtain the PHY device instance,
> +        * and then use that PHY device instance when triggering
> +        * the PHY reset.
> +        */
> +       if (!phy_dev && fep->phy_node)
> +               phy_dev = of_phy_find_device(fep->phy_node);
> +
> +       phy_reset_after_clk_enable(phy_dev);
> +}
> +
>  static int fec_enet_clk_enable(struct net_device *ndev, bool enable)
>  {
>         struct fec_enet_private *fep = netdev_priv(ndev);
> @@ -1938,7 +1956,7 @@ static int fec_enet_clk_enable(struct net_device
> *ndev, bool enable)
>                 if (ret)
>                         goto failed_clk_ref;
> 
> -               phy_reset_after_clk_enable(ndev->phydev);
> +               fec_enet_phy_reset_after_clk_enable(ndev);
>         } else {
>                 clk_disable_unprepare(fep->clk_enet_out);
>                 if (fep->clk_ptp) {
> @@ -2987,7 +3005,7 @@ fec_enet_open(struct net_device *ndev)
>          * phy_reset_after_clk_enable() before because the PHY wasn't
> probed.
>          */
>         if (reset_again)
> -               phy_reset_after_clk_enable(ndev->phydev);
> +               fec_enet_phy_reset_after_clk_enable(ndev);
> 
>         /* Probe and connect to PHY when open the interface */
>         ret = fec_enet_mii_probe(ndev);
> --
> 2.28.0

Tested-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>