On Fri, Aug 19, 2016 at 06:18:11PM +0530, Kedareswara rao Appana wrote:
> This patch fixes the below race conditions in the driver.
> ---> Fix Opps after unload the driver as a module
> ---> Use spin locks where relevant.
> ---> Take reference on the external phy to prevent issues
> when phy driver is unloaded.
Each one of these should be an individual patch.
>
> Reported-by: Andrew Lunn <and...@lunn.ch>
> Signed-off-by: Kedareswara rao Appana <appa...@xilinx.com>
> ---
> drivers/net/phy/xilinx_gmii2rgmii.c | 32 +++++++++++++++++++++++++++++++-
> 1 file changed, 31 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/phy/xilinx_gmii2rgmii.c
> b/drivers/net/phy/xilinx_gmii2rgmii.c
> index 7336fd0..cdd9d95 100644
> --- a/drivers/net/phy/xilinx_gmii2rgmii.c
> +++ b/drivers/net/phy/xilinx_gmii2rgmii.c
> @@ -34,6 +34,7 @@ struct gmii2rgmii {
> struct phy_driver *phy_drv;
> struct phy_driver conv_phy_drv;
> int addr;
> + spinlock_t phy_lock;
The phy already have a lock.
> };
>
> static int xgmiitorgmii_read_status(struct phy_device *phydev)
> @@ -55,7 +56,7 @@ static int xgmiitorgmii_read_status(struct phy_device
> *phydev)
> val |= BMCR_SPEED1000;
> else if (phydev->speed == SPEED_100)
> val |= BMCR_SPEED100;
> - else
> + else if (phydev->speed == SPEED_10)
> val |= BMCR_SPEED10;
I said you want to return an error is the PHY is using a speed your
converter cannot support. I don't see an error being raised here.
> err = mdiobus_write(phydev->mdio.bus, priv->addr, XILINX_GMII2RGMII_REG,
> @@ -71,6 +72,8 @@ int xgmiitorgmii_probe(struct mdio_device *mdiodev)
> struct device *dev = &mdiodev->dev;
> struct device_node *np = dev->of_node, *phy_node;
> struct gmii2rgmii *priv;
> + struct mii_bus *bus;
> + unsigned long flags;
>
> priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> if (!priv)
> @@ -88,17 +91,43 @@ int xgmiitorgmii_probe(struct mdio_device *mdiodev)
> return -EPROBE_DEFER;
> }
>
> + spin_lock_init(&priv->phy_lock);
> +
> + bus = priv->phy_dev->mdio.bus;
> + if (!try_module_get(bus->owner)) {
> + dev_err(dev, "failed to get the bus module\n");
> + return -EIO;
> + }
The comment at the top says you are taking a reference to the phy.
Here you take a reference to the mdio bus driver???
> +
> + get_device(&priv->phy_dev->mdio.dev);
> +
> priv->addr = mdiodev->addr;
> priv->phy_drv = priv->phy_dev->drv;
> memcpy(&priv->conv_phy_drv, priv->phy_dev->drv,
> sizeof(struct phy_driver));
> priv->conv_phy_drv.read_status = xgmiitorgmii_read_status;
> priv->phy_dev->priv = priv;
> + spin_lock_irqsave(&priv->phy_lock, flags);
> priv->phy_dev->drv = &priv->conv_phy_drv;
> + spin_unlock_irqrestore(&priv->phy_lock, flags);
And how is this spinlock protecting anything?
> +
> + dev_set_drvdata(dev, priv);
>
> return 0;
> }
>
> +static void xgmiitorgmii_remove(struct mdio_device *mdiodev)
> +{
> + struct gmii2rgmii *priv = dev_get_drvdata(&mdiodev->dev);
> + struct mii_bus *bus;
> +
> + bus = priv->phy_dev->mdio.bus;
> +
> + put_device(&priv->phy_dev->mdio.dev);
> + module_put(bus->owner);
> + phy_disconnect(priv->phy_dev);
Why are you disconnecting the phy?
> +}
> +
> static const struct of_device_id xgmiitorgmii_of_match[] = {
> { .compatible = "xlnx,gmii-to-rgmii-1.0" },
> {},
> @@ -107,6 +136,7 @@ MODULE_DEVICE_TABLE(of, xgmiitorgmii_of_match);
>
> static struct mdio_driver xgmiitorgmii_driver = {
> .probe = xgmiitorgmii_probe,
> + .remove = xgmiitorgmii_remove,
> .mdiodrv.driver = {
> .name = "xgmiitorgmii",
> .of_match_table = xgmiitorgmii_of_match,
> --
> 2.1.2
>
