2014-03-07 3:34 GMT-08:00 Sebastian Hesselbarth
<sebastian.hesselbarth@xxxxxxxxx>:
> commit 1211ce53077164e0d34641d0ca5fb4d4a7574498
> ("net: phy: resume/suspend PHYs on attach/detach")
> introduced a feature to suspend PHYs when entering halted state.
>
> Unfortunately, not all bootloaders properly power-up PHYs on reset
> and fail to access ethernet because the PHY is still powered down.
>
> Therefore, this adds code and documentation for a sysfs attribute to
> allow/deny PHYs to be suspended on a per-PHY basis. Disabling that
> attribute prevents PHYs from being suspended when entering halted state.
>
> Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@xxxxxxxxx>
> Reported-by: Andrew Lunn <andrew@xxxxxxx>
Looks good to me, thanks Sebastian!
Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
> ---
> David,
>
> I know I am late, but I still consider this as a fix for v3.14, therefore
> this is based on v3.14-rc1. If you are already done with taking fixes for
> v3.14, I can, of course, rebase this upon net-next.
>
> Cc: David Miller <davem@xxxxxxxxxxxxx>
> Cc: Rob Landley <rob@xxxxxxxxxxx>
> Cc: Andrew Lunn <andrew@xxxxxxx>
> Cc: Florian Fainelli <f.fainelli@xxxxxxxxx>
> Cc: netdev@xxxxxxxxxxxxxxx
> Cc: linux-doc@xxxxxxxxxxxxxxx
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> ---
> Documentation/ABI/testing/sysfs-bus-mdio | 10 ++++++++++
> drivers/net/phy/mdio_bus.c | 26 ++++++++++++++++++++++++++
> drivers/net/phy/phy_device.c | 5 +++++
> include/linux/phy.h | 2 ++
> 4 files changed, 43 insertions(+)
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-mdio b/Documentation/ABI/testing/sysfs-bus-mdio
> index 6349749ebc29..e85a3d350cb1 100644
> --- a/Documentation/ABI/testing/sysfs-bus-mdio
> +++ b/Documentation/ABI/testing/sysfs-bus-mdio
> @@ -7,3 +7,13 @@ Description:
> by the device during bus enumeration, encoded in hexadecimal.
> This ID is used to match the device with the appropriate
> driver.
> +
> +What: /sys/bus/mdio_bus/devices/.../phy_allow_suspend
> +Date: March 2014
> +KernelVersion: 3.14
> +Contact: netdev@xxxxxxxxxxxxxxx
> +Description:
> + This attribute contains a boolean parameter to allow (1) or
> + deny (0) MDIO bus attached PHYs to be suspended. Some
> + bootloaders fail to properly resume a suspended PHY, so this
> + can be used to prevent the PHY from being suspended.
> diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
> index 71e49000fbf3..811d35185596 100644
> --- a/drivers/net/phy/mdio_bus.c
> +++ b/drivers/net/phy/mdio_bus.c
> @@ -432,8 +432,34 @@ phy_id_show(struct device *dev, struct device_attribute *attr, char *buf)
> }
> static DEVICE_ATTR_RO(phy_id);
>
> +static ssize_t phy_allow_suspend_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct phy_device *phydev = to_phy_device(dev);
> +
> + return sprintf(buf, "%d\n", phydev->allow_suspend);
> +}
> +
> +static ssize_t phy_allow_suspend_store(struct device *dev,
> + struct device_attribute *attr, const char *buf, size_t count)
> +{
> + struct phy_device *phydev = to_phy_device(dev);
> + bool val;
> + int ret;
> +
> + ret = strtobool(buf, &val);
> + if (ret < 0)
> + return ret;
> +
> + phydev->allow_suspend = val;
> +
> + return count;
> +}
> +static DEVICE_ATTR_RW(phy_allow_suspend);
> +
> static struct attribute *mdio_dev_attrs[] = {
> &dev_attr_phy_id.attr,
> + &dev_attr_phy_allow_suspend.attr,
> NULL,
> };
> ATTRIBUTE_GROUPS(mdio_dev);
> diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
> index 4b03e63639b7..1c83d34d848b 100644
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -173,6 +173,7 @@ struct phy_device *phy_device_create(struct mii_bus *bus, int addr, int phy_id,
> dev->phy_id = phy_id;
> if (c45_ids)
> dev->c45_ids = *c45_ids;
> + dev->allow_suspend = true;
> dev->bus = bus;
> dev->dev.parent = bus->parent;
> dev->dev.bus = &mdio_bus_type;
> @@ -685,6 +686,10 @@ int phy_suspend(struct phy_device *phydev)
> struct phy_driver *phydrv = to_phy_driver(phydev->dev.driver);
> struct ethtool_wolinfo wol;
>
> + /* Do not suspend PHYs, if user disabled it */
> + if (!phydev->allow_suspend)
> + return -ENOSYS;
> +
> /* If the device has WOL enabled, we cannot suspend the PHY */
> wol.cmd = ETHTOOL_GWOL;
> phy_ethtool_get_wol(phydev, &wol);
> diff --git a/include/linux/phy.h b/include/linux/phy.h
> index 565188ca328f..c472e750c023 100644
> --- a/include/linux/phy.h
> +++ b/include/linux/phy.h
> @@ -272,6 +272,7 @@ struct phy_c45_device_ids {
> * c45_ids: 802.3-c45 Device Identifers if is_c45.
> * is_c45: Set to true if this phy uses clause 45 addressing.
> * is_internal: Set to true if this phy is internal to a MAC.
> + * allow_suspend: Set to false to prevent PHY suspend.
> * state: state of the PHY for management purposes
> * dev_flags: Device-specific flags used by the PHY driver.
> * addr: Bus address of PHY
> @@ -308,6 +309,7 @@ struct phy_device {
> struct phy_c45_device_ids c45_ids;
> bool is_c45;
> bool is_internal;
> + bool allow_suspend;
>
> enum phy_state state;
>
> --
> 1.8.5.3
>
--
Florian
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