From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Green Subject: Re: [RFC] usbnet: use eth%d name for known ethernet devices Date: Thu, 24 Mar 2011 13:44:28 +0000 Message-ID: <4D8B4ABC.9090203@linaro.org> References: <4D79F068.2080009@linaro.org> <1300924878.2638.38.camel@bwh-desktop> <201103241413.54599.arnd@arndb.de> <201103241415.45115.arnd@arndb.de> Reply-To: andy.green@linaro.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Ben Hutchings , Steve Calfee , Michal Nazarewicz , Randy Dunlap , broonie@opensource.wolfsonmicro.com, lkml , Nicolas Pitre , Greg KH , David Brownell , Alan Cox , grant.likely@secretlab.ca, Linux USB list , netdev@vger.kernel.org, Benjamin Herrenschmidt , roger.quadros@nokia.com, Jaswinder Singh , patches@linaro.org To: Arnd Bergmann Return-path: In-Reply-To: <201103241415.45115.arnd@arndb.de> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 03/24/2011 01:15 PM, Somebody in the thread at some point said: > The documentation for the USB ethernet devices suggests that > only some devices are supposed to use usb0 as the network interface > name instead of eth0. The logic used there, and documented in > Kconfig for CDC is that eth0 will be used when the mac address > is a globally assigned one, but usb0 is used for the locally > managed range that is typically used on point-to-point links. > > Unfortunately, this has caused a lot of pain on the smsc95xx > device that is used on the popular pandaboard without an > EEPROM to store the MAC address, which causes the driver to > call random_ether_address(). > > Obviously, there should be a proper MAC addressed assigned to > the device, and discussions are ongoing about how to solve > this, but this patch at least makes sure that the default > interface naming gets a little saner and matches what the > user can expect based on the documentation, including for > new devices. > > The approach taken here is to flag whether a device might be a > point-to-point link with the new FLAG_PTP setting in the usbnet > driver_info. A driver can set both FLAG_PTP and FLAG_ETHER if > it is not sure (e.g. cdc_ether), or just one of the two. > The usbnet framework only looks at the MAC address for device > naming if both flags are set, otherwise it trusts the flag. > > Signed-off-by: Arnd Bergmann > Cc: Andy Green > Cc: patches@linaro.org For Panda case at least, Tested-by: Andy Green -Andy