Messages in this thread | ![/](/images/icornerl.gif) | | Date | Tue, 6 Feb 2024 10:00:57 -0600 | From | Bjorn Helgaas <> | Subject | Re: [PATCH v2] PCI: vmd: Enable PCI PM's L1 substates of remapped PCIe Root Port and NVMe |
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On Tue, Feb 06, 2024 at 02:29:12PM +0200, Ilpo Järvinen wrote: > On Fri, 2 Feb 2024, Jian-Hong Pan wrote: > ...
> > +out_enable_link_state: > > + /* > > + * Make PCI devices at D0 when enable PCI-PM L1 PM Substates from > > + * Section 5.5.4 of PCIe Base Spec Revision 6.0 > > I don't understand what are you trying to say here? Are there some typos > or grammar errors or something entire missing from the comment?
This is about the fact that per sec 5.5.4, "If setting either or both of the enable bits for PCI-PM L1 PM Substates, both ports must be configured as described in this section while in D0."
We can wordsmith this a little, maybe:
Ensure devices are in D0 before enabling PCI-PM L1 PM Substates, per PCIe r6.0, sec 5.5.4.
I look a little askance at having to do this separately from pci_enable_link_state_locked(), but we can solve that elsewhere if need be.
> > + pci_set_power_state_locked(pdev, PCI_D0); > > + pci_enable_link_state_locked(pdev, PCIE_LINK_STATE_ALL);
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