On Thu, Sep 24, 2015 at 11:57:31PM +0200, Andrew Lunn wrote: > Hi Russell > > I tested both of these with my board. It is a Freescale Vybrid, using > the FEC ethernet driver, and i have three switches attached, using > mdio-mux to give three mdio busses. > > No obvious regressions, my board boots, the switches are all present > and correct. I built the FEC driver as a module, and it won't unload: > > kernel:unregister_netdevice: waiting for eth1 to become free. Usage count = 1 > unregister_netdevice: waiting for eth1 to become free. Usage count = 1 > > i assume because DSA holds a reference. I've not tried a fully module > build, DSA has issues with that. > > Tested-by: Andrew Lunn <andrew@xxxxxxx> Thanks for testing. Please could you confirm whether the same behaviour is observed without the patches, just to make absolutely sure that isn't a regression. However, I think you are correct - I'm unable to locate where in the DSA code: - dst->master_dev's dev_hold() is undone (hence a reference left) - dst is freed - dsa_probe() allocates it using kzalloc(), but dsa_remove() and it's children don't free this structure. There's no notifier which detects whether the underlying device has gone away - it registers a netdev notifier (dsa_slave_netdevice_event) but this only deals with slave devices, not the master device. Thanks. -- FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
