Re: [RFC 0/2] PCI/ASPM: Allow controller-defined default link state

[Manivannan Sadhasivam]

On Wed, Jul 16, 2025 at 11:12:45PM GMT, Kenneth R. Crudup wrote:
> 
> Unfortunately, having tested the patch (against Linus' master), it doesn't work.
> 
> I don't think the ASPM(?) state is making it to the VMD.
> 

Because, the VMD driver is not at all setting the PCI_BUS_FLAGS_NO_ASPM_DEFAULT
flag. But I proposed an alternate method [1] to enable ASPM which would avoid
using the flag.

- Mani

[1] https://lore.kernel.org/linux-pci/4xcwba3d4slmz5gfuwypavxqreobnigzyu4vib6powtbibytyp@mmqcns27vlyr/

> LMK if you need more info.
> 
> -Kenny
> 
> On Wed, 16 Jul 2025, David E. Box wrote:
> 
> > Testing is appreciated as I didn't get a chance to do so yet but plan to.
> 
> > Thanks, David
> >
> > ---
> >
> > David E. Box (2):
> >   PCI/ASPM: Allow drivers to provide ASPM link state via pci_bus
> >   PCI: vmd: Provide default ASPM link state for synthetic hierarchy
> >
> >  drivers/pci/controller/vmd.c |  7 +++++--
> >  drivers/pci/pcie/aspm.c      |  5 ++++-
> >  include/linux/pci.h          | 12 ++++++++----
> >  3 files changed, 17 insertions(+), 7 deletions(-)
> >
> >
> > base-commit: d0b3b7b22dfa1f4b515fd3a295b3fd958f9e81af
> >
> 
> -- 
> Kenneth R. Crudup / Sr. SW Engineer, Scott County Consulting, Orange County CA
> 

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