Re: [PATCH v7 0/5] PCI/ASPM: Add sysfs attributes for controlling ASPM

[Bjorn Helgaas <helgaas@kernel.org>]

On Sat, Oct 05, 2019 at 02:02:29PM +0200, Heiner Kallweit wrote:
> Background of this extension is a problem with the r8169 network driver.
> Several combinations of board chipsets and network chip versions have
> problems if ASPM is enabled, therefore we have to disable ASPM per
> default. However especially on notebooks ASPM can provide significant
> power-saving, therefore we want to give users the option to enable
> ASPM. With the new sysfs attributes users can control which ASPM
> link-states are disabled.
> 
> v2:
> - use a dedicated sysfs attribute per link state
> - allow separate control of ASPM and PCI PM L1 sub-states
> 
> v3:
> - patch 3: statically allocate the attribute group
> - patch 3: replace snprintf with printf
> - add patch 4
> 
> v4:
> - patch 3: add call to sysfs_update_group because is_visible callback
>            returns false always at file creation time
> - patch 3: simplify code a little
> 
> v5:
> - rebased to latest pci/next
> 
> v6:
> - patch 3: consider several review comments from Bjorn
> - patch 4: add discussion link to commit message
> 
> v7:
> - Move adding pcie_aspm_get_link() to separate patch 3
> - patch 4: change group name from aspm to link_pm
> - patch 4: control visibility of attributes individually
> 
> Heiner Kallweit (5):
>   PCI/ASPM: add L1 sub-state support to pci_disable_link_state
>   PCI/ASPM: allow to re-enable Clock PM
>   PCI/ASPM: Add and use helper pcie_aspm_get_link
>   PCI/ASPM: Add sysfs attributes for controlling ASPM link states
>   PCI/ASPM: Remove Kconfig option PCIEASPM_DEBUG and related code
> 
>  Documentation/ABI/testing/sysfs-bus-pci |  14 ++
>  drivers/pci/pci-sysfs.c                 |   6 +-
>  drivers/pci/pci.h                       |  12 +-
>  drivers/pci/pcie/Kconfig                |   7 -
>  drivers/pci/pcie/aspm.c                 | 252 ++++++++++++++++--------
>  include/linux/pci.h                     |  10 +-
>  6 files changed, 199 insertions(+), 102 deletions(-)

I applied these to pci/aspm for v5.5.  Thank you very much for all the
work you put into this!

There are a couple questions that are still open, but I have no
problem if we want to make minor tweaks before the merge window opens.

Bjorn