Messages in this thread | | | Date | Mon, 6 Jul 2009 21:50:09 -0400 (EDT) | From | Alan Stern <> | Subject | Re: PROBLEM: Nvidia OHCI chipset MCP78S (Geforce 8200) hangs on > 1Mbit transfers if noapic/acpi=noirq is missing |
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On Mon, 6 Jul 2009, Zbigniew Luszpinski wrote:
> I hope I find here someone who wrote or know Linux ohci driver so he/she knows > how to slow down ohci bulk/iso IO operations without breaking hotplug.
The speed of iso operations cannot be changed, because the transactions have to occur at a specified interval.
OHCI doesn't provide any way to slow down bulk operations either, once a bulk URB has been submitted. The best you can do is slow down the rate of submission. But you already tried that and it didn't work.
> It looks Linux ohci driver is more aggressive on ohci IO than windows one so > making Linux less timing demanding would help my MCP78S keep working.
I suspect you're looking in the wrong direction. There's probably something wrong at a deeper level, in the chipset drivers for instance.
Alan Stern
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