On Thu, Mar 17, 2011 at 09:40:42PM +0000, Mark Brown wrote: > On Thu, Mar 17, 2011 at 02:31:08PM -0700, Greg KH wrote: > > On Thu, Mar 17, 2011 at 09:24:49PM +0000, Mark Brown wrote: > > > > The way this is normally done is that the ethernet controller can be > > > attached to a SEPROM which it reads when it powers on. This will > > > contain a number of device configuration parameters, including the > > > vendor IDs and the MAC address, which will be configured before the > > > device makes itself available on the bus. If the system integrator has > > > omitted the SEPROM then the device will come up with defaults, usually > > > something like all zeros. > > > Ok, then again, let's deal with this on a case-by-case basis please, as > > this is going to be a "rare" thing in the real world. I don't want to > > encourage _any_ engineers to think that this is ok to do for USB > > devices. > > It's really not at all rare in the embedded world - the overwhelming > majority of the systems I've worked on have omitted the SEPROMS for > components that are soldered down in the system. It'd be pretty insane > to do it for things that are distinct USB devices but that's not the > case. > > There are good solid engineering reasons for doing things this way if > you've got any prospect of shifting any kind of volume, as well as the > cost saving achieved by removing a component you also simplify and most > likely speed up the production process as you can reduce the number of > components that need to be programmed on each system that gets built. > > > Patches to fix this, for this specific PandaBoard controller are gladly > > accepted. What's odd is this is explicitly a Linux development board, > > so you would think that this could have been caught, and fixed, in the > > hardware a long time ago, right? > > The way everyone resolves this stuff is by patching their kernel > locally. Well, that means that the device tree work is going to be useful here, right? :) Best of luck, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
