Shaohua Li wrote: > PCI Express ASPM defines a protocol for PCI Express components in the D0 > state to reduce Link power by placing their Links into a low power state > and instructing the other end of the Link to do likewise. This > capability allows hardware-autonomous, dynamic Link power reduction > beyond what is achievable by software-only controlled power management. > However, The device should be configured by software appropriately. > Enabling ASPM will save power, but will introduce device latency. > > This patch adds ASPM support in Linux. It introduces a global policy for > ASPM, a sysfs file /sys/module/pcie_aspm/parameters/policy can control > it. The interface can be used as a boot option too. Currently we have > below setting: > -default, BIOS default setting > -powersave, highest power saving mode, enable all available ASPM state > and clock power management > -performance, highest performance, disable ASPM and clock power > management > By default, the 'default' policy is used currently. > > In my test, power difference between powersave mode and performance mode > is about 1.3w in a system with 3 PCIE links. > > please review, any comments will be appreciated.
quickly glanced this over since I recently disabled l1 ASPM for the e1000/e1000e driven 82573 device which has issues with l1 ASPM. that immediately gives me the question: how can I continue to disable 1l aspm by default for this device using this infrastructure? I do like the fact that there is a generic way to re-enable it for the users who want to use it. Can this change be done when the device is already active? Can you change this parameter per device/module? > + /* Clock PM state*/ > + unsigned int clk_pm_capable:1; > + unsigned int clk_pm_enabled:1; > + unsigned int bios_clk_state:1; might want to get rid of these bitfields? Cheers, Auke -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
