On Tue, Sep 04, 2012 at 09:11:28AM +0200, Kurt Van Dijck wrote: > On Mon, Sep 03, 2012 at 10:54:49PM +0200, Oliver Hartkopp wrote: > > On 03.09.2012 20:29, Fabio Baltieri wrote: > > > > > On Mon, Sep 03, 2012 at 08:13:35PM +0200, Kurt Van Dijck wrote: > > >> On Mon, Sep 03, 2012 at 02:40:39PM +0200, Marc Kleine-Budde wrote: > > >>> The net->ifindex is unique. But it's only an integer. Usually can0 has a > > >>> ifindex != 0, so a simple can%d is contra productive here. > > >>> > > >>> Some pointers to related code: > > >>> http://lxr.free-electrons.com/source/drivers/base/core.c#L1847 > > >>> http://lxr.free-electrons.com/source/drivers/base/core.c#L73 > > >>> http://lxr.free-electrons.com/source/include/linux/device.h#L695 > > >>> > > >>> comments? > > > > > > That would probabily makes really hard to choose the right > > > default_trigger for led devices to get to the appropriate CAN LED in > > > embedded systems, as trigger name would depend from other network > > > devices and probing order (correct me if I'm wrong). > > > > > > Something with device name would probaily be more appropriate here. > > > > > >> > > >> a very recent idea: something with netdevice notifiers and > > >> NETDEV_CHANGENAME ... > > >> http://lxr.free-electrons.com/source/net/core/dev.c#L1030 > > >> > > >> you could: rename the trigger, or if we think it's usefull, > > >> block the netdev rename when its triggers are in use. > > > > > > Blocking the rename looks overkill to me, > > renaming a netdev _after_ first attaching led triggers looks stupid to me > anyway. > > > > what about using device name > > > with an optional "port id" appended to it? Sounds simpler... > > > > > > The name of the device can only be changed when the interface is down. > > Is it possible to put some scripting around it to detach and attach the leds > > to the interfaces on ifup/ifdown triggers? > > Are the led triggers available for using while the netdev is down then?
Sure! On embedded systems triggers are usually attached to actual LEDs at probe time using default_trigger field of struct led_classdev, and that can be specified both in machine files or in device tree. See http://lxr.free-electrons.com/source/arch/powerpc/boot/dts/mpc8315erdb.dts#L477 http://lxr.free-electrons.com/source/arch/arm/mach-pxa/tosa.c#L576 that's why the trigger name should be predictable, at least at boot/probe time. The actual CAN LED trigger also reflects the actual state of the interface (off if down, on if up, blink on activity). Fabio -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
