[SOLVED] USB Mass Storage Device (EHCI) problems with OHCI

deen · n00b Joined: 25 Dec 2006 Posts: 28 Location: /germany/bw

I'm using 2.6.19-gentoo-r5 and have tried ehci-ohcd and ohci-hcd as compiled-in and as modules. When the ohci-hcd-module is loaded, the cached reads also get to the USB 2.0 level, but the buffered disk reads stay at 1 MB/s. (measurement done with hdparm -tT) But with the ohci-hcd unloaded, the buffered disk reads get up to 20 MB/s, which is the maximum speed of the disk.
Anyone has an idea why ohci is blocking the buffered disk reads of my ehci-connected-Disk? (it really works with the ehci-module according to dmesg)

erik258 · Posted: Wed Mar 28, 2007 9:48 pm Post subject:

I'm guessing the problem might be that your device is plugged into a usb < 2 port. From menuconfig:

deen · n00b Joined: 25 Dec 2006 Posts: 28 Location: /germany/bw

I've already tried to use the EHCI Root Hub Transaction Translator, but it didn't change anything.
And I also think the OHCI module steals the control, but how to stop it doing that?

erik258 · Posted: Thu Mar 29, 2007 4:06 pm Post subject:

don't use the ohci module -- just use ehci !
_________________
Configuring a Firewall? Try my iptables configuration
LinuxCommando.com is my blog for linux-related scraps and tidbits. Stop by for a visit!

deen · n00b Joined: 25 Dec 2006 Posts: 28 Location: /germany/bw

I've also tried that, but my USB-1.1-Devices, like my mouse don't work then. What's the reason for that? For example, on the grml-0.9-liveCD my usb-hdd works with full speed as well as my mouse.

deen · n00b Joined: 25 Dec 2006 Posts: 28 Location: /germany/bw

erik258 · Posted: Sat Apr 07, 2007 4:47 pm Post subject:

I don't know why it wouldn't work. Maybe my understanding of what the root hub translators do is wrong, or maybe your system is out of date, your bios needs updating or reconfiguring, or the hardware on your pc is buggy (not bloody likely! unless it's on a via apollo chipset...) The only other thing I can think of is that maybe you should be using usb-uhci instead of ohci ... most Intel and Via chips use UHCI, whilst nforce-based boards and compaq boards seem to use OHCI. The help on OHCI kernel support suggests checking lspci -v to see which you need. However, I don't think modules without corresponding hardware would be likely to mess stuff up. While I was there, I noticed that the help file on

deen · n00b Joined: 25 Dec 2006 Posts: 28 Location: /germany/bw

I'm using an nforce2-based mainboard, so I have to use OHCI and not UHCI.
I've already tried to enable the "Improved Transaction Translator scheduling" in my kernel, but it is without any effect.

deen · n00b Joined: 25 Dec 2006 Posts: 28 Location: /germany/bw

Little update: Although my USB-HDD is still recognized as a USB-2.0-Device and being accessed by ehci-hcd, now high-speed-disk-reads don't work at all; even with ohci-hcd not loaded.
I don't know the reason for that, because I didn't even change my kernel... (still using 2.6.19-r5, but I also tried 2.6.20-r5 -> same problem)

deen · n00b Joined: 25 Dec 2006 Posts: 28 Location: /germany/bw

Nobody has an idea?

deen · n00b Joined: 25 Dec 2006 Posts: 28 Location: /germany/bw

I really hate pushing, but the hdd-speed is so annoying.
Edit: WTF: I did neither change nor update anything but now it works with USB-2.0-speed.

Edit2: After a reboot it isn't working anymore, have to find the problem...
Edit3: Found it: The problem has to be somewhere in hdparm, which shows me the high speed only after I copied something on the disk. BTW: Copying always works fast. :roll: