From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux Subject: Re: [PATCH net] net: phy: Fix lack of reference count on PHY driver Date: Fri, 3 Feb 2017 09:54:27 +0000 Message-ID: <20170203095427.GA27312@n2100.armlinux.org.uk> References: <20170201024643.2050-1-f.fainelli@gmail.com> <20170202.215407.606581158337251076.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: f.fainelli@gmail.com, netdev@vger.kernel.org, andrew@lunn.ch, maowenan@huawei.com To: David Miller Return-path: Received: from pandora.armlinux.org.uk ([78.32.30.218]:49996 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753038AbdBCJyp (ORCPT ); Fri, 3 Feb 2017 04:54:45 -0500 Content-Disposition: inline In-Reply-To: <20170202.215407.606581158337251076.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Feb 02, 2017 at 09:54:07PM -0500, David Miller wrote: > Hot plugging PHYs and notifications and all of that business is > net-next material. I was talking more about unbinding of the driver, which is something that can be done today, eg: $ ls -l /sys/bus/mdio_bus/drivers/Atheros\ 8035\ ethernet/ total 0 lrwxrwxrwx 1 root root 0 Feb 3 09:49 2188000.ethernet:00 -> ../../../../devices/soc0/soc/2100000.aips-bus/2188000.ethernet/mdio_bus/2188000.ethernet/2188000.ethernet:00 --w------- 1 root root 4096 Feb 3 09:49 bind --w------- 1 root root 4096 Feb 3 09:49 uevent --w------- 1 root root 4096 Feb 3 09:49 unbind $ echo 2188000.ethernet:00 > /sys/bus/mdio_bus/drivers/Atheros\ 8035\ ethernet/unbind is all it takes, and the same oops will happen. Try it on a box you don't care about crashing. :) This is my point - locking the module into the kernel using try_module_get() doesn't actually fix the problem where drivers are concerned, it just has the illusion of being safe. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net.