USB console and network devices unsupported for boot

USB console and network devices unsupported for boot

[VomLehn]

I've been tracking down a problem with kernels 2.6.28 and 2.6.29 and it looks
like there is a race condition with using USB boot devices. Specifically:

o	The console specified with console=ttyUSB0 does not work
o	Using ip=169.254.0.21::169.254.0.21:255.255.0.0:zeus:eth0: does not
	configure eth0.

Both of these issues arise because the required USB devices aren't ready
when the rest of the kernel wants to initialize them and there is no way
to make the initialization wait for the devices. I opened a bug for this
and you can see the discussion of this issue, with alternative approaches, at:

	http://bugzilla.kernel.org/show_bug.cgi?id=12944

but the bottom line is that this is not regarded as a bug.

My question: are USB serial consoles and auto-configured network devices in
common use or is my application a special case? If the former, we need to push
for a better resolution. Otherwise, I'll go off and figure out something that
works for my application.
--
David VomLehn

Re: USB console and network devices unsupported for boot

[Tim Bird]

VomLehn wrote:
> My question: are USB serial consoles and auto-configured network devices in
> common use or is my application a special case? If the former, we need to push
> for a better resolution. Otherwise, I'll go off and figure out something that
> works for my application.

I'd say that they're not uncommon during development, but I
(personally) don't know of any shipped products with either of
these.
 -- Tim

=============================
Tim Bird
Architecture Group Chair, CE Linux Forum
Senior Staff Engineer, Sony Corporation of America
=============================

Re: USB console and network devices unsupported for boot

[VomLehn]

On Fri, Mar 27, 2009 at 12:12:08PM -0700, Tim Bird wrote:
> VomLehn wrote:
> > My question: are USB serial consoles and auto-configured network devices in
> > common use or is my application a special case? If the former, we need to push
> > for a better resolution. Otherwise, I'll go off and figure out something that
> > works for my application.
> 
> I'd say that they're not uncommon during development, but I
> (personally) don't know of any shipped products with either of
> these.

Good point. This is definitely a question about development phase use of USB.
--
David VomLehn