On Thu, Sep 13, 2018 at 05:33:12PM +0300, Mika Westerberg wrote: > Hi all, > > This patch series aims to allow PCIe hierarchies enter D3cold both during > system sleep and runtime, including PCIe hotplug ports. > > The motivation of this series are recent systems such as Lenovo Thinkpad X1 > Carbon 6th gen and upcoming Dell laptops where the Thunderbolt controller > is always present in the system (pretty much like what Apple systems have > been doing for years). Because it is always present it consumes energy so > it is important to power it off when idle. > > The PCIe root port hosting the Thunderbolt controller and all the connected > external PCIe devices includes a standard ACPI power resource and related > methods _PR3, _PR0, _PRW and _DSW that take care of the actual transition > to D3cold and back to D0. > > With current kernels entering system sleep states leaves the root port into > D3hot which means the ACPI power resource is still on. This is bad when > system enters suspend-to-idle (all these systems are s2idle only) because > the BIOS is not involved and the devices are effectively left on, consuming > battery unnecessarily. > > Patches 1-4 add D3cold support for system sleep and the subsequent patches > do the same for runtime PM. > > In case someone wants to try out runtime PM, the xHCI controller that is > part of the PCIe switch below the root port needs to have runtime PM > "unblocked" manually (this will be automatic in future). > > For Thinkpad: > > # echo auto > /sys/bus/pci/devices/0000:3b:00.0/power/control > > For Dell: > > # echo auto > /sys/bus/pci/devices/0000:39:00.0/power/control > > Note if the root port enters D3cold, running things like 'lspci' brings it > back t0 D0 (because PCI config space is not accessible in D3cold) so if one > wants to check out the power state without accidentally bringing the device > back into D0 needs to do that indirectly. If the root port is 1d.0 power > state can be checked: > > # cat /sys/bus/pci/devices/0000:00:1d.0/power/runtime_status > suspended > # cat /sys/bus/pci/devices/0000:00:1d.0/firmware_node/real_power_state > D3cold > > Even if this again revolves around Thunderbolt I think these apply to any > PCIe system supporting D3cold. > > These patches apply on top of pci.git pci/hotplug. The previus version of > the series can be viewed here: > > https://www.spinics.net/lists/linux-acpi/msg83841.html > > Changes from v1: > > * Updated comment in patch [1/10] according what Rafael suggested > * Added empty line in patch [2/10] > * Check for !pciehp_poll_mode in [4/10] > * Use DPM_FLAG_NEVER_SKIP instead of DPM_FLAG_SMART_PREPARE which > simplifies patch [5/10] signicantly > * Use const in acpi_data_get_property() and change int -> unsigned int > in patch [9/10] > * Added tags > > Mika Westerberg (10): > PCI: Do not skip power managed bridges in pci_enable_wake() > PCI / ACPI: Enable wake automatically for power managed bridges > PCI: pciehp: Disable hotplug interrupt during suspend > PCI: pciehp: Do not handle events if interrupts are masked > PCI: portdrv: Resume upon exit from system suspend if left runtime suspended > PCI: portdrv: Add runtime PM hooks for port service drivers > PCI: pciehp: Implement runtime PM callbacks > PCI/PME: Implement runtime PM callbacks > ACPI / property: Allow multiple property compatible _DSD entries > PCI / ACPI: Whitelist D3 for more PCIe hotplug ports > > drivers/acpi/property.c | 97 ++++++++++++++++++++++--------- > drivers/acpi/x86/apple.c | 2 +- > drivers/gpio/gpiolib-acpi.c | 2 +- > drivers/pci/hotplug/pciehp.h | 2 + > drivers/pci/hotplug/pciehp_core.c | 37 ++++++++++++ > drivers/pci/hotplug/pciehp_hpc.c | 16 ++++- > drivers/pci/pci-acpi.c | 57 +++++++++++++++++- > drivers/pci/pci.c | 18 +++++- > drivers/pci/pci.h | 3 + > drivers/pci/pcie/pme.c | 27 +++++++++ > drivers/pci/pcie/portdrv.h | 4 ++ > drivers/pci/pcie/portdrv_core.c | 20 +++++++ > drivers/pci/pcie/portdrv_pci.c | 14 ++--- > include/acpi/acpi_bus.h | 8 ++- > include/linux/acpi.h | 9 +++ > 15 files changed, 273 insertions(+), 43 deletions(-) Applied the whole series (not just 01/10, which I applied by itself for some reason) to pci/hotplug for v4.20, thanks!
