Gentoo Archives: gentoo-amd64

From: "Kevin F. Quinn" <kevquinn@g.o>
To: gentoo-amd64@l.g.o
Subject: [gentoo-amd64] forcedeth weirdness - a bedtime story
Date: Wed, 23 Aug 2006 22:48:15
1 Just figured out a nasty forcedeth network issue, so here's the details
2 if anyone is interested.
4 My new amd64 box, a cheap Compaq desktop (AMD64 3800+, nVidia
5 MCP51 chipset), doesn't start the network properly when booting of the
6 2006.0 livecd (or universal cd, for that matter). Obviously it came
7 with Windows XP, and I'm setting it up to dual boot with Gentoo on a
8 second SATA drive (drives are cheap, and it saves having to risk
9 resizing the NTFS partitions).
11 I'd gone as far as buying a (cheap!) PCI network card; installed it and
12 booted from the CD - only to discover that not only did the new card
13 configure properly, but so did the on-board forcedeth one, that failed
14 consistently before! So, removed the PCI card, booted up and yes, the
15 forcedeth stuff came up fine again. Bizarre.
17 Later, I rebooted to Windows for a while, then shutdown and rebooted
18 from the livecd again - only to find the network was failing again! :(
19 At this point, it occurred to me that perhaps there is something the
20 Windows driver does to the chip that the forcedeth driver fails to
21 reset, leaving the chip in a not-working state. Pulled the power cord
22 out, stuffed it back in thinking this would ensure the device was reset
23 properly - but no :( still it failed.
25 Crawled under the desk to put the PCI card back in again, and noticed
26 that after pulling the power cord out the power supply led remained lit
27 for quite some seconds (5 to 10!). Ahah - fancy-pants PSU, I thought;
28 obviously pulling the cable out and re-inserting it isn't enough to
29 remove power. After the light had gone out, just powered up again
30 (without putting the PCI card in after all) and lo, the interface came
31 up fine.
33 So the moral of the story is, if you're switching between Windows and
34 Linux and see this problem, the way to get around it is to completely
35 remove power and wait long enough for the PSU to switch off completely
36 before powering up.
38 I suspect later kernel versions may have this fixed - quite a few
39 changes went in to the forcedeth driver around 2.17.3, but until I have
40 the kernel built I can't say...
42 BTW anyone else think of the "Master Control Program" whenever you see
43 "nVidia MCP51" ;)
45 --
46 Kevin F. Quinn


File name MIME type
signature.asc application/pgp-signature


Subject Author
Re: [gentoo-amd64] forcedeth weirdness - a bedtime story Chris Forsyth <chris.forsyth@×××××××××.net>