Hi Mayurkumkar, On 3/25/2017 5:38 PM, Sinan Kaya wrote: > 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 v4 (http://www.spinics.net/lists/linux-pci/msg59245.html) > ------------------------ > - pci_aspm_init(): Fix function comment. Called for every device we > enumerate. > Upstream link partner: Shouldn't need to check pdev->link_state > (should always be NULL for a brand-new device). > > - pcie_aspm_init_link_state(): Called for bridges (upstream end of > link) after all children have been enumerated. No longer needs to > check aspm_support_enabled or pdev->has_secondary_link or the VIA > quirk: pci_aspm_init() already checked that stuff, so we only need > to check pdev->link_state here. > > - split the last patch into two > PCI/ASPM: move link_state cleanup to bridge remove > PCI/ASPM: save power on values during bridge init > > - create bugzilla (https://bugzilla.kernel.org/show_bug.cgi?id=194895) > - add fixes tags > > Sinan Kaya (4): > PCI/ASPM: introduce pci_aspm_init() and add to pci_init_capabilities() > 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 > > drivers/pci/pcie/aspm.c | 93 +++++++++++++++++++++++++++++++++---------------- > drivers/pci/probe.c | 3 ++ > drivers/pci/remove.c | 3 +- > include/linux/pci.h | 2 ++ > 4 files changed, 69 insertions(+), 32 deletions(-) > Can you test this on your system and provide your tested-by if all good? Sinan -- Sinan Kaya Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project. -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
