[PATCH 2/2] net: fec: Only unregister MII bus if we registered it

[Ramon Fried]

On Fri, Apr 9, 2021 at 12:10 AM Sean Anderson <sean.anderson at seco.com> wrote:
>
> If we fail to probe for whatever reason, we cannot unregister/free the
> MII bus unless we registered it with fec_get_miibus. This fixes FECs
> sharing an MDIO bus from destroying it, preventing the other FEC from
> using it.
>
> Fixes: 6a895d039b ("net: Update eQos driver and FEC driver to use eth phy interfaces")
>
> Signed-off-by: Sean Anderson <sean.anderson at seco.com>
> ---
>
>  drivers/net/fec_mxc.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/fec_mxc.c b/drivers/net/fec_mxc.c
> index 37eb894248..a64ba955a5 100644
> --- a/drivers/net/fec_mxc.c
> +++ b/drivers/net/fec_mxc.c
> @@ -1355,6 +1355,7 @@ static void fec_gpio_reset(struct fec_priv *priv)
>
>  static int fecmxc_probe(struct udevice *dev)
>  {
> +       bool dm_mii_bus = true;
>         struct eth_pdata *pdata = dev_get_plat(dev);
>         struct fec_priv *priv = dev_get_priv(dev);
>         struct mii_dev *bus = NULL;
> @@ -1462,6 +1463,7 @@ static int fecmxc_probe(struct udevice *dev)
>  #endif
>
>         if (!bus) {
> +               dm_mii_bus = false;
>  #ifdef CONFIG_FEC_MXC_MDIO_BASE
>                 bus = fec_get_miibus((ulong)CONFIG_FEC_MXC_MDIO_BASE,
>                                      dev_seq(dev));
> @@ -1507,8 +1509,10 @@ static int fecmxc_probe(struct udevice *dev)
>         return 0;
>
>  err_phy:
> -       mdio_unregister(bus);
> -       free(bus);
> +       if (!dm_mii_bus) {
> +               mdio_unregister(bus);
> +               free(bus);
> +       }
>  err_mii:
>  err_timeout:
>         fec_free_descs(priv);
> --
> 2.25.1
>
Reviewed-by: Ramon Fried <rfried.dev at gmail.com>