[PATCH V8 0/5] PCI/ASPM: reconfigure ASPM following hotplug for POLICY_DEFAULT

[Patel, Mayurkumar]

>
>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

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