At Fri, 6 Jan 2006 04:24:22 +0000, Pavel Machek wrote: > > > > > > 1.) most sound cards have more than two states. (once again latency over > > > > power savings trade offs) > > > > > > What is the latency in typical "most sound card" case? > > > > ACPI requires within 100ms for D1 and D2. D3 can be longer. > > Spec is useless here. 1usec is <100msec. Do you know any > soundcard that takes >10msec from D3? In the case of D3, the driver needs to initialize fully, and a latency longer than 10ms may easily happen espeically with HZ=100. Most of codec chips have powersave modes (disable converters and amps), so having a "powersave" state makes sense, not only "on" and "suspend". Takashi
