On Wed, Oct 31, 2018 at 10:36:22AM +0000, David Howells wrote: > Sean Young <sean@xxxxxxxx> wrote: > > > > > Devices have a MAC address available, which is printed during boot: > > > > Not all dvb devices have a mac address. > > How do I tell? If it's all zeros it's not there? The mac gets populated through read_mac_address member of dvb_usb_device_properties. If that's not called (or does not succeed), then there is no mac address. I think you can safely assume that if it's all 0's then it was not read. > > Devices without a mac address shouldn't have a mac_dvb sysfs attribute, > > I think. > > I'm not sure that's possible within the core infrastructure. It's a class > attribute set when the class is created; I'm not sure it can be overridden on > a per-device basis. > > Possibly the file could return "" or "none" in this case? That's very ugly. Have a look at, for example, rc-core wakeup filters: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/media/rc/rc-main.c#n1844 > > The dvb type and dvb adapter no is already present in the device name, > > I'm not sure why this needs duplicating. > > They can be used with ATTR{} in udev rules. I'm not clear that the name can. See my other email. KERNEL=="dvb[0-9]+\.demux\.[0-9]+" > > With this patch, with a usb Hauppauge Nova-T Stick I get: > > ... > > ==> /sys/class/dvb/dvb0.demux0/dvb_mac <== > > 00:00:00:00:00:00 > > I can't say why that happens. I don't have access to this hardware. Should > it have a MAC address there? Is the MAC address getting stored in > dvbdev->adapter->proposed_mac? Maybe it's not getting read - on the card I > use it's read by the cx23885 driver... I think... The nova-t-usb2.c file > doesn't mention proposed_mac. This is a dib0700-type device (much older). Sean
