Re: 64-bit DMA problems with BCM4312 using b43

[Larry Finger]

On 11/13/2009 03:13 PM, Matthew Garrett wrote:
> On Fri, Nov 13, 2009 at 03:05:18PM -0600, Larry Finger wrote:
> 
>> I'm in the process of creating a patch to set the latency to 200 usec. The
>> default is 2000. On my fast prosessors, it should not be anything nearly that
>> slow. If we determine this to be the problem, then we can try tuning.
> 
> The latency is the amount of time it takes to get out of deep C states 
> and into C0. That's a function of the processor design rather than the 
> frequency.

Thanks for your suggestion. The value of 200 fixed one of the two machines and
greatly improved the other. He is currently testing with a value of 150, and
will try 100 if that still fails.

Larry


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