On 11/16/2016 06:47 AM, Johan Hovold wrote:
> Make sure to drop the reference taken by of_phy_find_device() when
> registering and deregistering the fixed-link PHY-device.
>
> Note that we need to put both references held at deregistration.
>
> Fixes: 39b0c705195e ("net: dsa: Allow configuration of CPU & DSA port
> speeds/duplex")
> Signed-off-by: Johan Hovold <jo...@kernel.org>
> ---
>
> Hi,
>
> This is one has been compile tested only, but fixes a couple of leaks
> similar to one that was found in the cpsw driver for which I just posted
> a patch.
>
> It turns out all drivers but DSA fail to deregister the fixed-link PHYs
> registered by of_phy_register_fixed_link(). Due to the way this
> interface was designed, deregistering such a PHY is a bit cumbersome and
> looks like it would benefit from a common helper.
>
> However, perhaps the interface should instead be changed so that the PHY
> device is returned so that drivers do not need to use
> of_phy_find_device() when they need to access properties of the fixed
> link (e.g. as in dsu_cpu_dsa_setup below).
>
> Thoughts?
>
> Thanks,
> Johan
>
>
> net/dsa/dsa.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/net/dsa/dsa.c b/net/dsa/dsa.c
> index a6902c1e2f28..798a6a776a5f 100644
> --- a/net/dsa/dsa.c
> +++ b/net/dsa/dsa.c
> @@ -233,6 +233,8 @@ int dsa_cpu_dsa_setup(struct dsa_switch *ds, struct
> device *dev,
> genphy_read_status(phydev);
> if (ds->ops->adjust_link)
> ds->ops->adjust_link(ds, port, phydev);
> +
> + phy_device_free(phydev); /* of_phy_find_device */
> }
>
> return 0;
> @@ -509,8 +511,12 @@ void dsa_cpu_dsa_destroy(struct device_node *port_dn)
> if (of_phy_is_fixed_link(port_dn)) {
> phydev = of_phy_find_device(port_dn);
> if (phydev) {
> - phy_device_free(phydev);
> fixed_phy_unregister(phydev);
> + /* Put references taken by of_phy_find_device() and
> + * of_phy_register_fixed_link().
> + */
> + phy_device_free(phydev);
> + phy_device_free(phydev);
Double free, this looks bogus here. Actually would not this mean a
triple free since you already free in dsa_cpu_dsa_setup() which is
paired with dsa_cpu_dsa_destroy()?
--
Florian
