[PATCH V6 0/5] PCI/ASPM: reconfigure ASPM following hotplug for POLICY_DEFAULT

[Patel, Mayurkumar]

Hi Sinan

>
>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 v5 (https://www.spinics.net/lists/arm-kernel/msg571758.html)
>------------------------
>- rebase to 4.11-rc3
>- Split pci_aspm_init() body into pci_aspm_init_upstream()
>  and pci_aspm_init_downstream() for bridge and endpoint
>  specific code behavior.
>- Get rid of function0 function.
>  Detect downstream link in pci_aspm_init_upstream() instead
>
>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 for quick patches. I can boot up now without any crash. I will test actual
functionality by next week as I am out for this week.




> drivers/pci/pcie/aspm.c | 137 ++++++++++++++++++++++++++++++++----------------
> drivers/pci/probe.c     |   3 ++
> drivers/pci/remove.c    |   3 +-
> include/linux/pci.h     |   2 +
> 4 files changed, 98 insertions(+), 47 deletions(-)
>
>--
>1.9.1

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