Re: USB regression (and other failures) in 2.6.2[45]* - mostly resolved

From: Andrew Buehler
Date: Tue Feb 19 2008 - 15:36:22 EST


On 2/16/2008 10:35 PM, Alan Stern wrote:

On Sat, 16 Feb 2008, Andrew Buehler wrote:

Until this thread, I was not even aware that ACPI was related to
USB; I had largely conflated it with a similar acronym which I
think is related to power management and which I can suddenly not
even find in my kernel config. I will, however, look into
linux-acpi.

ACPI isn't directly related to USB; rather it has to do with
transferring information between the OS and the
BIOS/vendor-specific-hardware. Power management is example where such
a transfer is needed. In your case, the relevant information is
which IRQ is connected to which motherboard device. If you don't have
ACPI enabled in your configuration, then perhaps that's the problem
-- try enabling it.

Apparently it was the problem; enabling ACPI has fixed not only the USB
problem but also the network problem (somewhat miraculously, since I'm
quite certain that I had ACPI enabled in a 2.6.23.x kernel where the
network did not work despite an apparently matching driver).

I feel somewhat foolish for having reported a regression over what turns
out to have been a simple misconfiguration, but I still do think it's
somewhat misleading at best for something so potentially important to
completely non-power-related things to be buried under the heading of
power management... I would suggest moving it somewhere else in the
config and the dependencies, except that I have neither a suggestion for
a possible place nor any idea of how much actual work that would
involve.



With those two problems out of the way, what is left is the hard-drive
issue, and that is also halfway fixed by enabling ACPI. Specifically, it
is "fixed" in that the kernel sees the hard drive and I can mount it,
but it is not fixed in that the program we need to use in this
environment does not see the drive.

I have a config from a boot disc running 2.6.5 (that's not a typo) under
which the program in question *does* see the drive, but there are
massive differences between that config and the one I am using now, and
narrowing the critical difference down is likely to be somewhat
difficult - particularly since some of the "differences" are merely
renamed config symbols (i.e. the CONFIG_SCSI_SATA_*->CONFIG_SATA_*
switchover), and I have limited ability to tell which without intensive
investigation. Are there any established techniques for simplifying this
kind of comparison?

--
Andrew Buehler
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