ACK: [SRU] [L/M/Unstable] [PATCH 0/9] Enable ASPM for NVMe behind VMD

[Tim Gardner]

On 9/6/23 1:54 AM, Kai-Heng Feng wrote:
> BugLink: https://bugs.launchpad.net/bugs/2034504
> 
> [Impact]
> ASPM of NVMe behind VMD is not enabled when BIOS FADT doesn't allow ASPM
> to be modified.
> That causes higher overall power consumption.
> 
> [Fix]
> Allow ASPM to be enabled.
> While at this, remove old cruft that can interfere upstream VMD driver.
> 
> [Test]
> Check the value of `/sys/kernel/debug/pmc_core/slp_s0_residency_usec`.
> Now system can reach deepest power saving state during sleep.
> 
> [Where problems could occur]
> Some NVMe may have I/O issue when ASPM is enabled. But for this scenario
> the issue will also appear when VMD is disabled.
> 
> David E. Box (3):
>    PCI: vmd: Use PCI_VDEVICE in device list
>    PCI: vmd: Create feature grouping for client products
>    PCI: vmd: Add quirk to configure PCIe ASPM and LTR
> 
> Kai-Heng Feng (5):
>    Revert "UBUNTU: SAUCE: vmd: fixup bridge ASPM by driver name instead"
>    Revert "UBUNTU: SAUCE: PCI/ASPM: Enable LTR for endpoints behind VMD"
>    Revert "UBUNTU: SAUCE: PCI/ASPM: Enable ASPM for links under VMD
>      domain"
>    UBUNTU: SAUCE: PCI/ASPM: Allow ASPM override over FADT default
>    UBUNTU: SAUCE: PCI: vmd: Mark ASPM override for device behind VMD
>      bridge
> 
> Michael Bottini (1):
>    PCI/ASPM: Add pci_enable_link_state()
> 
>   drivers/pci/controller/vmd.c | 100 ++++++++++++++++++++++++++---------
>   drivers/pci/pcie/aspm.c      |  54 +++++++++++++++++++
>   drivers/pci/quirks.c         |  68 ------------------------
>   include/linux/pci.h          |   7 +++
>   4 files changed, 135 insertions(+), 94 deletions(-)
> 
Acked-by: Tim Gardner <tim.gardner at canonical.com>
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Tim Gardner
Canonical, Inc