On Mon, 2011-11-21 at 12:51 -0800, Greg KH wrote: > On Mon, Nov 21, 2011 at 09:38:33AM -0800, Guy, Wey-Yi wrote: > > On Mon, 2011-11-21 at 10:26 -0800, Greg KH wrote: > > > On Mon, Nov 21, 2011 at 09:20:29AM -0800, Guy, Wey-Yi wrote: > > > > Hi John/Garrett/Greg, > > > > > > > > We test the ASPM patch with the Intel WiFi devices on number of > > > > platforms and the improvement is huge. > > > > > > What "ASPM patch"? > > > > https://lkml.org/lkml/2011/11/11/212 > > Ok, yet you feel that my statement there is not sufficient right now? oh, I am just want to let you know we test this patch and the result is very good, it make huge improvement with our devices. > > > > > In the "idle associated" mode, the power consumption number for our new > > > > devices down to ~40mW range from over 120mW. > > > > > > > > We will do more testing but I will suggest to apply this patch to the > > > > stable release. > > > > > > What is the git commit id of this patch? Have you read > > > Documentation/stable_kernel_rules.txt for how to properly submit a patch > > > to the stable kernel trees? > > You failed to answer this :( oh here is the patch already in linux-next tree commit 7f92c4f7d92a7558ed7eb29fa59e1c98402dc3c2 Author: Matthew Garrett <mjg@xxxxxxxxxx> Date: Thu Nov 10 16:38:33 2011 -0500 PCI: Rework ASPM disable code Right now we forcibly clear ASPM state on all devices if the BIOS indicates that the feature isn't supported. Based on the Microsoft presentation "PCI Express In Depth for Windows Vista and Beyond", I'm starting to think that this may be an error. The implication is that unless the platform grants full control via _OSC, Windows will not touch any PCIe features - including ASPM. In that case clearing ASPM state would be an error unless the platform has granted us that control. This patch reworks the ASPM disabling code such that the actual clearing of state is triggered by a successful handoff of PCIe control to the OS. The general ASPM code undergoes some changes in order to ensure that the ability to clear the bits isn't overridden by ASPM having already been disabled. Further, this theoretically now allows for situations where only a subset of PCIe roots hand over control, leaving the others in the BIOS state. It's difficult to know for sure that this is the right thing to do - there's zero public documentation on the interaction between all of these components. But enough vendors enable ASPM on platforms and then set this bit that it seems likely that they're expecting the OS to leave them alone. Measured to save around 5W on an idle Thinkpad X220. Signed-off-by: Matthew Garrett <mjg@xxxxxxxxxx> Signed-off-by: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx> Thanks Wey -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
