Hi Sinan >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 > Thanks for your patches. I am seeing kernel panic after applying these patches (on top of latest kernel) each time during early boot in pci_aspm_init() (any hints already?) function. Need to check if it's something related to my local setup or it's because of these changes. For now I don't have more details why it crashes but I will dig in further and I will provide you more data as soon as I have it. >-- >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. 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
