> >When the operating system is booted with the default ASPM policy >(POLICY_DEFAULT), current code is querying the enable/disable >states from ASPM registers to determine the policy. > >For example, a BIOS could set the power saving state to performance >and clear all ASPM control registers. A balanced ASPM policy could >enable L0s and disable L1. A power conscious BIOS could enable both >L0s and L1 to trade off latency and performance vs. power. > >After hotplug removal, pcie_aspm_exit_link_state() function clears >the ASPM registers. An insertion following hotplug removal reads >incorrect policy as ASPM disabled even though ASPM was enabled >during boot. > >This is caused by the fact that same function is used for reconfiguring >ASPM regardless of the power on state. > >------------------------ >Changes from v7 (https://www.spinics.net/lists/arm-kernel/msg573034.html) >------------------------ >- enable LTSSM as a best effort if the endpoint is not connected during > boot > > >Sinan Kaya (5): > PCI/ASPM: introduce pci_aspm_init() and add to pci_init_capabilities() > PCI/ASPM: split pci_aspm_init() into two > PCI/ASPM: add init hook to device_add > PCI/ASPM: save power on values during bridge init > PCI/ASPM: move link_state cleanup to bridge remove > Thanks Sinan for new patches. No issues seen so far in my testing for L1 and L1SS both. May you please add my tested-by in the patches? I will keep on testing it and let you know if something goes wrong for any corner case. > drivers/pci/pcie/aspm.c | 149 +++++++++++++++++++++++++++++++++--------------- > drivers/pci/probe.c | 3 + > drivers/pci/remove.c | 3 +- > include/linux/pci.h | 2 + > 4 files changed, 110 insertions(+), 47 deletions(-) > >-- >1.9.1 Intel Deutschland GmbH Registered Address: Am Campeon 10-12, 85579 Neubiberg, Germany Tel: +49 89 99 8853-0, www.intel.de Managing Directors: Christin Eisenschmid, Christian Lamprechter Chairperson of the Supervisory Board: Nicole Lau Registered Office: Munich Commercial Register: Amtsgericht Muenchen HRB 186928
