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path: root/drivers/pci/pcie/aspm.c
AgeCommit message (Collapse)Author
2009-07-02PCI: disable ASPM on VIA root-port-under-bridge configurationsShaohua Li
commit 8e822df700694ca6850d1e0c122fd7004b2778d8 upstream. VIA has a strange chipset, it has root port under a bridge. Disable ASPM for such strange chipset. Tested-by: Wolfgang Denk <wd@denx.de> Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-02-12PCI: properly clean up ASPM link state on device removeAlex Chiang
commit 3419c75e15f82c3ab09bd944fddbde72c9e4b3ea upstream. We only want to disable ASPM when the last function is removed from the parent's device list. We determine this by checking to see if the parent's device list is completely empty. Unfortunately, we never hit that code because the parent is considered an upstream port, and never had an ASPM link_state associated with it. The early check for !link_state causes us to return early, we never discover that our device list is empty, and thus we never remove the downstream ports' link_state nodes. Instead of checking to see if the parent's device list is empty, we can check to see if we are the last device on the list, and if so, then we know that we can clean up properly. Cc: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-01-24PCI: keep ASPM link state consistent throughout PCIe hierarchyShaohua Li
commit 46bbdfa44cfc0d352148a0dc33ba9f6db02ccdf0 upstream. In a PCIe hierarchy with a switch present, if the link state of an endpoint device is changed, we must check the whole hierarchy from the endpoint device to root port, and for each link in the hierarchy, the new link state should be configured. Previously, the implementation checked the state but forgot to configure the links between root port to switch. Fixes Novell bz #448987. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Tested-by: Andrew Patterson <andrew.patterson@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-12-13PCIe: ASPM: Break out of endless loop waiting for PCI config bits to switchThomas Renninger
commit 2a42d9dba7842422ffb2c02e75288a8bc2fd5065 upstream. Makes a Compaq 6735s boot reliably again. It used to hang in the loop on some boots. Give the link one second to train, otherwise break out of the loop and reset the previously set clock bits. Signed-off-by: Thomas Renninger <trenn@suse.de> Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Matthew Garrett <mjg59@srcf.ucam.org> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-09-16PCI: Fix pcie_aspm=forceSitsofe Wheeler
pcie_aspm=force did not work because aspm_force was being double negated leading to the sanity check failing. Moving a bracket should fix this. Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Sitsofe Wheeler <sitsofe@yahoo.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-07-28PCI: add an option to allow ASPM enabled forciblyShaohua Li
A new option, pcie_aspm=force, will force ASPM to be enabled, even on system with PCIe 1.0 devices. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-07-28PCI: disable ASPM on pre-1.1 PCIe devicesShaohua Li
Disable ASPM on pre-1.1 PCIe devices, as many of them don't implement it correctly. Tested-by: Jack Howarth <howarth@bromo.msbb.uc.edu> Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-07-28PCI: disable ASPM per ACPI FADT settingShaohua Li
The ACPI FADT table includes an ASPM control bit. If the bit is set, do not enable ASPM since it may indicate that the platform doesn't actually support the feature. Tested-by: Jack Howarth <howarth@bromo.msbb.uc.edu> Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-05-21PCI: don't enable ASPM on devices with mixed PCIe/PCI functionsShaohua Li
The Slot 03:00.* of JMicron controller has two functions, but one is PCIE endpoint the other isn't PCIE device, very strange. PCIE spec defines all functions should have the same config for ASPM, so disable ASPM for the whole slot in this case. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-04-20PCI: add PCI Express ASPM supportShaohua Li
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. Note: some devices might not work well with aspm, either because chipset issue or device issue. The patch provide API (pci_disable_link_state), driver can disable ASPM for specific device. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-02Revert "PCI: PCIE ASPM support"Greg Kroah-Hartman
This reverts commit 6c723d5bd89f03fc3ef627d50f89ade054d2ee3b. It caused build errors on non-x86 platforms, config file confusion, and even some boot errors on some x86-64 boxes. All around, not quite ready for prime-time :( Cc: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-01PCI: PCIE ASPM supportShaohua Li
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. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>