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SubjectUSB Storage speed regression since 2.6.12
    Hi all :)

I don't know if this is a known issue, but usb-storage speed for
'Full speed' devices dropped from 2.6.11.12 (more than 800Kb/s) to
2.6.12 (less than 250Kb/s). The problem still exists in 2.6.13.

The lack of speed seems to affect only the OHCI driver. My test
was done over a PCI USB 2.0 card, ALi chipset, OHCI driver (well
EHCI+OHCI) and using a full speed device capable of 12MBps. The
average measured speeds are:

- 2.4.31: about 450Kb/seg
- 2.6.11-Debian: about 800Kb/seg
- 2.6.11.12: about 820Kb/seg
- 2.6.12.x: about 200Kb/seg
- 2.6.13: about 200Kb/seg

The .config is more or less the same in all kernels. I've took a
look at the ChangeLog for 2.6.12 and there are lots of changes in the
USB subsystem but I cannot identify which one could be the culprit.

If anyone needs more information (for example, device
identification in all kernels) just tell. I don't provide much more
information since this can be a known issue and so there is no need
to pollute the list with a long .config and dmesg output...

Thanks in advance :)

Raúl Núñez de Arenas Coronado

--
Linux Registered User 88736 | http://www.dervishd.net
http://www.pleyades.net & http://www.gotesdelluna.net
It's my PC and I'll cry if I want to...
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