Gentoo Archives: gentoo-amd64

From: Duncan <1i5t5.duncan@×××.net>
To: gentoo-amd64@l.g.o
Subject: [gentoo-amd64] Re: USB 2.0 falling back to full-speed
Date: Wed, 10 Sep 2008 15:50:58
Message-Id: pan.2008.09.10.15.50.45@cox.net
In Reply to: Re: [gentoo-amd64] Re: USB 2.0 falling back to full-speed by Raffaele BELARDI
1 Raffaele BELARDI <raffaele.belardi@××.com> posted 48C7ADE8.3020300@××.com,
2 excerpted below, on Wed, 10 Sep 2008 13:22:16 +0200:
3
4 > Regarding usb loaded as module, the only syslog difference I found with
5 > the compiled-in version is that in the former ehci is loaded after ohci,
6 > while in the latter it is loaded before ohci.
7 >
8 > Is there a way to force the kernel to initialize/invoke drivers in a
9 > specific order with compiled-in drivers?
10
11 I believe there is... at least in some cases... using the kernel command
12 line in grub. It's not something I've tried nor do I remember the
13 details, unfortunately.
14
15 The config description for ehci says root-hubs are paired with an ohci/
16 uhci hub as well, for 1.1 fallback, and suggesting that you configure in
17 the appropriate one of those as well, which you did. In theory,
18 therefore, both should work regardless of which one starts first.
19 Obviously the theory doesn't match this implementation. I'd be surprised
20 if there wasn't either an ordering mechanism (user-side) or an in-kernel
21 quirk list regarding start order, however, just because hardware bugs
22 happen.
23
24 As for CPU throttling, after reading that bug (
25 http://bugzilla.kernel.org/show_bug.cgi?id=8692 ), it appears they
26 /tried/ to avoid having sensitive operations going on during frequency
27 changes. But that was well after boot and everything was initialized.
28 It's entirely possible they still need to modify the boot to stabilize
29 frequencies while initializing the drivers, as well. If you're up to a
30 lot of testing (well, it's obvious from that bug how many rounds it could
31 take...), you might consider filing a bug on it and see what they say.
32 Since you can't say it's a regression from a known working version, they
33 may not be quite as willing to work on it, but then again, they know what
34 fixed it in the up and running case, so fixing it during initialization
35 as well shouldn't be so hard.
36
37 But anyway, I'm glad my info was of help getting it working in some
38 fashion, even if it's not your first config choice. I guess you're lucky
39 you found both triggers at about the same time. Consider the chances if
40 you'd not thought to try them together!
41
42 --
43 Duncan - List replies preferred. No HTML msgs.
44 "Every nonfree program has a lord, a master --
45 and if you use the program, he is your master." Richard Stallman

Replies

Subject Author
Re: [gentoo-amd64] Re: USB 2.0 falling back to full-speed Raffaele BELARDI <raffaele.belardi@××.com>