Hi, Andrew
On 2017/6/29 4:28, Andrew Lunn wrote:
>>> >From your description, it sounds like you can call phy_resume() on a
>>> device which is not suspended.
>> Do you mean after calling dev_close, the device is still not suspended?
>
> You only call dev_close() if the device is running. What if somebody
> runs the self test on an interface when it has never been opened? It
> looks like you will call phy_resume(). But since it has never been
> suspended, you could be in trouble.
Here is what I can think of:
1. when the mac driver is first loaded, the phy has a default state. suspended?
2. If user runs the self test after using 'ifconfig ethX down', then I suppose
phy is already suspended.
Also I don't quite understand what do you mean by in trouble. Right now in phy
core, phy_resume return ok even the phy is not suspended.
Best Regards
Yunsheng Lin
>>
>> In general, suspend is expected to
>>> store away state which will be lost when powering down a
>>> device. Resume writes that state back into the device after it is
>>> powered up. So resuming a device which was never suspended could write
>>> bad state into it.
>>
>> Do you mean phydev->suspended has bad state?
>
> phy_resume() current does not check the phydev->suspended state.
>
>>> Also, what about if WOL has been set before closing the device?
>>
>> phy_suspend will return errro.
>>
>> int phy_suspend(struct phy_device *phydev)
>> {
>> struct phy_driver *phydrv = to_phy_driver(phydev->mdio.dev.driver);
>> struct ethtool_wolinfo wol = { .cmd = ETHTOOL_GWOL };
>> int ret = 0;
>>
>> /* If the device has WOL enabled, we cannot suspend the PHY */
>> phy_ethtool_get_wol(phydev, &wol);
>> if (wol.wolopts)
>> return -EBUSY;
>>
>> if (phydev->drv && phydrv->suspend)
>> ret = phydrv->suspend(phydev);
>>
>> if (ret)
>> return ret;
>>
>> phydev->suspended = true;
>>
>> return ret;
>> }
>
> Which means when you call phy_resume() in lb_setup() you are again
> resuming a device which is not suspended...
>
> Andrew
>
> .
>
