On Fri, Sep 02, 2022 at 02:11:12PM -0700, Sathyanarayanan Kuppuswamy wrote: > On 9/2/22 1:38 PM, Bjorn Helgaas wrote: > > On Fri, Sep 02, 2022 at 10:24:05AM -0700, Sathyanarayanan Kuppuswamy wrote: > >> On 9/2/22 7:58 AM, Bjorn Helgaas wrote: > >>> From: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> > >>> > >>> When disabling PTM, there's no need to clear the Root Select bit. We > >>> disable PTM during suspend, and we want to re-enable it during resume. > >>> Clearing Root Select here makes re-enabling more complicated. > >> > >> Currently, it looks like we disable PCI_PTM_CTRL_ROOT in pci_disable_ptm(), > >> but not enable it in pci_enable_ptm(). Do you know this did not trigger an > >> issue? > ... > > Thanks for asking this, because it reminds me why I didn't add > > pci_enable_ptm() calls in the resume paths! That would make them > > parallel with the suspend paths, which would definitely be nice. But > > we would have to rework pci_enable_ptm() to work for Root Ports and > > Switch Ports as well. I think we *could* do that. What do you think? > > IMO, the code will look better if we keep the suspend and resume paths in > sync. Since we are calling pci_disable_ptm() in suspend path, it makes > sense to call pci_enable_ptm() in resume path. > > Making the pci_enable_ptm() handle root and upstream ports should not > be very complicated, right? I took a stab at it. pci_enable_ptm() is getting kind of ugly, but maybe it's better overall. I'll post it and you can see what you think.
