Is there a way in Grub to enable USB 1.0 instead of USB 2.0?

edomingox · 04-29-2011, 01:04 AM

I'm getting a USB error -71 and I found that disabling ehci_hcd allows my USB port to be usable. When the server boots up, ehci is automatically loaded and once that happens, the USB is rendered useless. Is there a command in Grub to downgrade the USB version?

Another option would be to make an .img to load up without USB 2.0 and using USB 1.0 but I don't know how to make one.

toothandnail · 04-29-2011, 02:20 AM

Quote:

Originally Posted by edomingox

I'm getting a USB error -71 and I found that disabling ehci_hcd allows my USB port to be usable. When the server boots up, ehci is automatically loaded and once that happens, the USB is rendered useless. Is there a command in Grub to downgrade the USB version?

Another option would be to make an .img to load up without USB 2.0 and using USB 1.0 but I don't know how to make one.

You don't say what distribution you are using, which makes it a bit difficult....

Most distributions have a mechanisim for blacklisting kernel modules. Have a look in /etc for whatever your distro uses for the purpose and put the ehci_hcd module in the blacklist. That should sort the problem out.

Paul.

edomingox · 04-29-2011, 04:57 AM

Forgot. I'm using Fedora 8. I know I can do the modprobe -r ehci_hcd to remove it and it works fine. But the problem I have is that command only works after the kernel is loaded. I get no keyboard response after it passes the Grub menu. So, whenever I get an error with the superblock or going through fsck, I cannot interact through IPMI remotely.

I know Grub has the nousb command. I don't want to do that. I already tried irqpoll and that didn't work.

toothandnail · 04-29-2011, 06:23 AM

In Fedora (if I remember correctly, haven't run it for a long time), you need to modify /etc/modeprobe.conf. Syntax should be:

Code:

alias ehci_hcd off

That should prevent the module loading in the first place. I'm not sure if that has any effect if the module is loading due to an intrd. If that is the case, rebuilding the initrd might be your only option.

Paul

edomingox · 04-30-2011, 10:51 AM

i believe the module is built into the kernel. ya, i think i'll have to rebuild the initrd. I never done it before so i'm unsure how to successfully do it. I don't have a test machine to do it on.