Re: Intel GemniLake xHCI connected devices can never wake up the system from suspend

[Mathias Nyman]

On 15.03.2018 15:28, Chris Chiu wrote:
> On Thu, Mar 15, 2018 at 7:46 PM, Mathias Nyman
> <mathias.nyman@xxxxxxxxxxxxxxx> wrote:
> > On 15.03.2018 06:40, Chris Chiu wrote:
> > > Hi,
> > >       I  have a ASUS AIO V222GA and another Acer Desktop XC-830 both
> > > have Intel CPU J5005 and they both hit the same problem. The XHCI
> > > connected USB keyboard/mouse can never wakeup the system from suspend.
> > > It reminds me that similiar thing happens on ApolloLake too which
> > > needs the XHCI_PME_STUCK_QUIRK to get it work. It's also mentioned in
> > >
> > > https://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/pentium-celeron-n-series-spec-update.pdf
> > > page #14 for N-seris intel CPU. And I also find the same problem
> > > description in
> > > https://www.intel.com/content/dam/www/public/us/en/documents/product-briefs/silver-celeron-spec-update.pdf
> > > page #16 for J-series Intel CPU. Seems that they have different
> > > workaround so I can not simply apply XHCI_PME_STUCK_QUIRK to make it
> > > work.
> > >
> > >       Anyone can help here?
> >
> > N-Series
> > CHP8: USB xHCI Controller May Not Re-Enter D3 State After a USB Wake Event
> > - needs XHCI_PME_STUCK_QUIRK in driver (sets bit 28 at offset 80a4)
> >
> > Intel Pentium Silver N5000
> > Intel Pentium Silver J5005
> > Intel Celeron N4000 and N4100
> > Intel Celeron J4105 and J4005
> >
> > USB xHCI Controller May Not Re-enter a D3 State After a USB Wake Even
> > Need to clear PME_EN bit of of the standard PCI PM_CSR register.
> > I think Linux does this anyway (clears enabling PME when reaching D0)
> > So if I remember correct there was no specific workaround needed for this.
> >
> > what is the PCI ID of your xhci controller? (lspci -nn)
>
> They're both 8086:31a8. So you mean from the workaround description, it should
> work w/o any extra code? "Software should clear bit 8 (PME_EN) of PM_CSR" has
> been handled somewhere else?
>
> > One other possible cause is that xHCI never reaches PCI device D3 suspend
> > state during system suspend.
> > xHC can't generate PME# wake event from normal running PCI device D0 state.
> >
> > PCI code in Linux will check with ACPI about the lowest possible D state
> > when suspending,
> > If there is something missing from the xHCI entry in ACPI DSDT table it
> > might select D0.
> > as the suspend state, causing wake failure.
>
> Here's the DSDT ASL of the ASUS machine.
> https://gist.github.com/mschiu77/8e9c8a0e5a98b70a6dfff45620340bf1

Scope (_SB.PCI0.XHC) has _PS0 method, so Linux will look for a _S3W to get the
lowest possible D state in S3, but_S3W is missing, so Linux pci-acpi code will
probably default to D0

> ASUS said the BIOS has no problem on USB wakeup under Windows so I don't think
> there's any update. Anything else could be cause for this?

Linux and Windows probably check different DSDT values

You can try to force your xHC to D3 during suspend with a hack:

diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 7815768..da46c52 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -488,6 +488,10 @@ static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
        else
                d_max = ACPI_STATE_D3_COLD;
        acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL, d_max);
+
+       if (pdev->device == 0x31a8)
+               acpi_state = ACPI_STATE_D3_HOT;
+
        if (acpi_state < 0)
                return PCI_POWER_ERROR;
 
and see if usb wake starts to work

-Mathias