Messages in this thread | | | Subject | Re: [PATCH NET V5 2/2] net: hns: Use phy_driver to setup Phy loopback | From | Yunsheng Lin <> | Date | Thu, 29 Jun 2017 10:35:25 +0800 |
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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 > > . >
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