Talk:Hardware Power Domains: Difference between revisions
JordanCrouse (talk | contribs) (C1 power consumption) |
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= Power Domain Discussion = |
= Power Domain Discussion = |
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== CaFe Chip, SD Controller Section == |
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If the SD-Card would be switched into MMC mode, then IIRC the only way back is to power cycle the SD-card. --[[User:Frief|Frief]] 03:58, 13 September 2006 (EDT) |
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== No support for optional ACPI Sleep state S2 == |
== No support for optional ACPI Sleep state S2 == |
Revision as of 07:58, 13 September 2006
Power Domain Discussion
CaFe Chip, SD Controller Section
If the SD-Card would be switched into MMC mode, then IIRC the only way back is to power cycle the SD-card. --Frief 03:58, 13 September 2006 (EDT)
No support for optional ACPI Sleep state S2
- S2 is uninteresting. IMHO - its a vague state literally defined as "higher latency then S1 but lower latency then S3". Not sure if your itention here is to mention that S2 *should*
be supported, or just commenting that it isn't. - JordanCrouse (Talk to me!) 18:58, 12 September 2006 (EDT)
C1 Test
This confused me for a second - what you're talking about is really more of a poor man's S1 - turning off pratically everything we can, turn off the PIT, and then enable wakeup devices and go to a hlt. A more correct name might be low-latency S1, because it will be slower then a C state transition (obivously) but it should be faster then a S1 transition.
This is quite similar to a tickless system, except that we turn off more devices. The only question is - how quickly can we turn off and turn on the un-needed devices, and does that latency fit within the average idle timesice of a nominally busy kernel? I believe that we can measure the average length between timeouts in the kernel with Systemtap - that would be useful information to have. If we can make this all fit - it would be a heck of a cool thing. - JordanCrouse (Talk to me!) 19:16, 12 September 2006 (EDT)
Another question - keeping in mind that we can't lose context in this mode - what devices would we possibly shut off that would have an effect on the total power consumption during C1? - JordanCrouse (Talk to me!) 19:40, 12 September 2006 (EDT)