Matthew Dharm said:
> On Sun, Feb 12, 2006 at 07:28:34PM -0700, Dwight Tovey wrote:
>>
>> Alan Stern said:
>> >
>> > It could simply be a case of hardware (in the computer's USB
>> controller)
>> > that's not quite up to snuff. 2.6 transfers data to/from USB mass
>> > storage devices faster than 2.4; perhaps the controller can't
>> handle it perfectly.
>> >
>> > Sorry I can't offer any more help. At least you do have 2.4.25 as a
>> fallback position.
>> >
>>
>> I'm pretty sure it is the hardware. We've found that running the same
>> tests on different systems with decent USB controllers works fine. If
>> we could, we would move to better USB hardware.
>>
>> You mentioned that 2.6 kernels transfer data faster than 2.4 and that
>> our current controllers probably can't handle the increased speed. Is
>> there any way that to slow the transfer rate?
>
> You could lower max_sectors in the SCSI device structure (either via
> sysfs or scsiglue.c).
>
Matthew -
Thanks for the response. Still no joy though. We used sysfs to drop it
to 8 sectors, and it still failed.
> You could also add an inter-command delay (similar to what the code does
> for Genesys logic devices).
>
Could you expand on this idea? I assume that you mean adding a delay
between SCSI commands? Could you point me to the code for this? It's
been a long time since I've had to do any real kernel hacking, and that
was for networking code in AIX, not Linux. Any pointers would be greatly
appreciated.
/dwight
--
Dwight N. Tovey
Director of Product Engineering
EmergeCore Networks
email: [EMAIL PROTECTED]
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