On May 26, 2017 8:34:18 PM PDT, Florian Fainelli <f.faine...@gmail.com> wrote:
>Some Ethernet drivers will attach/connect to a PHY device before
>calling
>register_netdevice() which is responsible for calling
>netdev_register_kobject()
>which would do the network device's kobject initialization. In such a
>case,
>sysfs_create_link() would return -ENOENT because the network device's
>kobject
>is not ready yet, and we would fail to connect to the PHY device.
>
>In order to keep things simple and symetrical, we just take the success
>path as
>indicative of the ability to access the network device's kobject, and
>create
>the second link if that's the case.
>
>Fixes: 5568363f0cb3 ("net: phy: Create sysfs reciprocal links for
>attached_dev/phydev")
>Reported-by: Woojung Hung <woojung....@microchip.com>
>Signed-off-by: Florian Fainelli <f.faine...@gmail.com>
>---
> drivers/net/phy/phy_device.c | 28 ++++++++++++++++++++--------
> include/linux/phy.h | 2 ++
> 2 files changed, 22 insertions(+), 8 deletions(-)
>
>diff --git a/drivers/net/phy/phy_device.c
>b/drivers/net/phy/phy_device.c
>index f84414b8f2ee..523366bd705a 100644
>--- a/drivers/net/phy/phy_device.c
>+++ b/drivers/net/phy/phy_device.c
>@@ -960,15 +960,25 @@ int phy_attach_direct(struct net_device *dev,
>struct phy_device *phydev,
>
> phydev->attached_dev = dev;
> dev->phydev = phydev;
>+
>+ /* Some Ethernet drivers try to connect to a PHY device before
>+ * calling register_netdevice() -> netdev_register_kobject() and
>+ * does the dev->dev.kobj initialization. Here we only check for
>+ * success which indicates that the network device kobject is
>+ * ready. Once we do that we still need to keep track of whether
>+ * links were successfully set up or not for phy_detach() to
>+ * remove them accordingly.
>+ */
> err = sysfs_create_link(&phydev->mdio.dev.kobj, &dev->dev.kobj,
> "attached_dev");
>- if (err)
>- goto error;
>+ if (!err) {
>+ err = sysfs_create_link(&dev->dev.kobj, &phydev->mdio.dev.kobj,
>+ "phydev");
>+ if (err)
>+ goto error;
>
>- err = sysfs_create_link(&dev->dev.kobj, &phydev->mdio.dev.kobj,
>- "phydev");
>- if (err)
>- goto error;
>+ phydev->sysfs_links = true;
>+ }
>
We should not assume that this Boolean will be true or false if we enter this
function a second time, v2 coming.
--
Florian
