On Wed, 10 Jan 2024, Bjorn Helgaas wrote: > On Wed, Jan 10, 2024 at 07:24:31AM -0800, David E. Box wrote: > > On Thu, 2023-12-28 at 18:30 -0600, Bjorn Helgaas wrote: > > > On Thu, Dec 28, 2023 at 04:31:12PM -0600, Bjorn Helgaas wrote: > > > > On Wed, Dec 20, 2023 at 05:12:50PM -0800, David E. Box wrote: > > > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > > > > index 55bc3576a985..3c4b2647b4ca 100644 > > > > > --- a/drivers/pci/pci.c > > > > > +++ b/drivers/pci/pci.c > > > > > > > > @@ -1579,7 +1579,7 @@ static void pci_restore_pcie_state(struct pci_dev > > > > > *dev) > > > > > { > > > > > ... > > > > > > > > + So we restore here only the > > > > > + * LNKCTL register with the ASPM control field clear. ASPM will > > > > > + * be restored in pci_restore_aspm_state(). > > > > > + */ > > > > > + val = cap[i++] & ~PCI_EXP_LNKCTL_ASPMC; > > > > > + pcie_capability_write_word(dev, PCI_EXP_LNKCTL, val); > > > > > > > > When CONFIG_PCIEASPM is not set, we will clear ASPMC here and never > > > > restore it. I don't know if this ever happens. Do we need to worry > > > > about this? Might firmware restore ASPMC itself before we get here? > > > > What do we want to happen in this case? > > > > I just checked this. L1 does get disabled which we don't want. We > > need to save and restore the BIOS ASPM configuration even when > > CONFIG_PCIEASPM is not set. > > There's some other ASPM stuff that we want even when CONFIG_PCIEASPM > is not set. I think some of that code is currently in probe.c and > pci.c. > > I can't find it right now, but we had some discussion about moving > that code into aspm.c, compiling aspm.c unconditionally, and adding > CONFIG_PCIEASPM ifdefs inside it for these cases. Maybe this is the > time do to that? If so, probably a preliminary patch or two to do > the code movement without any functional changes, followed by the > actual fixes. Hi, It's here: https://lore.kernel.org/linux-pci/20231011200442.GA1040348@bhelgaas/ I'm still not even half way done with the update for that patch series because I got stuck while attempting to do the rtsx driver changes the new way and moved to work on other stuff for a while. So far I've only tentatively placed some #ifdef into aspm.c but it wasn't all thought nor well arranged yet to limit the number of needed #ifdefs so nothing ready to be posted yet. And therefore not much effort is lost if David wants to take a look at it instead in the meantime. -- i.