On Tue, 23 Jan 2007, Len Brown wrote: > BTW. what model Thinkpad do you have? I own a ThinkPad T43 with ATI graphics (I wish I had bought one with Intel graphics, but they only had the crap screens on those), but I don't know if Mike Perry has a ThinkPad at all. It's just that whatever his laptop model, these issues are probably generic ones. Just FYI, the T43 runs 2.6.20-rc5+acpi-test without any new problems. I didn't try the acpi-acpica branch yet, though. > The USB dependency is probably due to USB bus mastering causing > the system to "pop" out of C3 to snoop the USB DMA traffic. EHCI seems to not share the same issue. OTOH, it draws a noticeable ammount of power, so I end up rmmod'ing it (and uhci-hcd) when not using anything USB. > You can get rid of it by disabling USB. But it sounds like in the full-on case > you've got an issue even with USB disabled. Or sometimes you can > bias the system to simply not enter C3 if it sees bus master traffic with > > # echo 0xFFFFFFFF > /sys/module/processor/parameters/bm_history Hmm, this one is neat. I will add it to the wiki. > Another thing to try building the kernel with CONFIG_HZ=100 -- which > is what a kernel for most laptops should be using in the first place. Well, actually we should be using *tickless* kernels, and start a witch hunt on userspace braindamage that wakes too often, but we are not there yet. -- "One disk to rule them all, One disk to find them. One disk to bring them all and in the darkness grind them. In the Land of Redmond where the shadows lie." -- The Silicon Valley Tarot Henrique Holschuh - To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
