RE: Variable ticks

From: Lee Revell
Date: Mon Jul 25 2005 - 16:27:28 EST


On Mon, 2005-07-25 at 17:19 -0400, Brown, Len wrote:
> >>>Question one, are there other actions to consider?
> >>
> >>
> >> Yes.
> >> Speaking for ACPI C3 state, note that DMA also
> >> wakes up the CPU -- even if there was no device interrupt.
> >> (aka, "the trouble with USB")
> >
> >Trouble? Why would USB do DMA unless there was a device activity?
>
> look here:
> http://www.google.com/search?hl=en&q=usb+selective+suspend
>
> Linux is working on it too, but it is in development.

What about audio? If there is a sound server running then you're going
to have a constant stream of interrupts and DMA activity from the sound
card even if the machine is idle and there aren't any sounds playing.

Lee

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