On Tue, May 19, 2020 at 10:57 AM Johan Hovold <johan@xxxxxxxxxx> wrote: > > On Wed, Apr 29, 2020 at 02:12:24PM +0200, Linus Walleij wrote: > > > to something that is device-unique, like "xr-gpios-<serial number>" > > > which makes it easy to locate the GPIOs on a specific serial converter > > > for lab use. However the USB serial maintainers know better what > > > to use here. Whatever makes a USB-to-serial unique from a TTY > > > point of view is probably fine with me too. > > > > > > My idea is that people might want to know which USB cable > > > this is sitting on, so I have this USB cable and from this label > > > I can always figure out which GPIO device it is. > > I think we've had this discussion before. First, not every device has a > unique serial number. Second, we already have a universal way of > distinguishing devices namely by using the bus topology. That's > available through sysfs and shouldn't have to be be re-encoded by every > driver in the gpiochip name. I remember I even referred to this myself, but I've been waning a bit on it recently, because it turns out that userspace/users aren't very good at parsing sysfs for topology. For userspace other than udev there seems to be a kind of agreement gap. Dunno how best to bridge it though. Education maybe. Yours, Linus Walleij
