Re: [PATCH] PCI / ACPI: Don't clear pme_poll on device that has unreliable ACPI wake

Kai Heng Feng
2019-01-24T15:29:37Z

> On Jan 24, 2019, at 11:15 PM, Bjorn Helgaas <helgaas@kernel.org> wrote:
>
> On Wed, Jan 23, 2019 at 03:17:37PM +0800, Kai Heng Feng wrote:
>>> On Jan 23, 2019, at 7:51 AM, Bjorn Helgaas <helgaas@kernel.org> wrote:
>>> On Tue, Jan 22, 2019 at 02:45:44PM +0800, Kai-Heng Feng wrote:
>>>> There are some e1000e devices can only be woken up from D3 one time, by
>>>> plugging ethernet cable. Subsequent cable plugging does set PME bit
>>>> correctly, but it still doesn't get woken up.
>>>>
>>>> Since e1000e connects to the root complex directly, we rely on ACPI to
>>>> wake it up. In this case, the GPE from _PRW only works once and stops
>>>> working after that.
>>>>
>>>> So introduce a new PCI quirk, to avoid clearing pme_poll flag for buggy
>>>> platform firmwares that have unreliable GPE wake.
>>>
>>> This quirk applies to all 0x15bb (E1000_DEV_ID_PCH_CNP_I219_LM7) and
>>> 0x15bd (E1000_DEV_ID_PCH_CNP_I219_LM6) devices. The e1000e driver
>>> claims about a zillion different device IDs.
>>>
>>> I would be surprised if these two devices are defective but all the
>>> others work correctly. Could it be that there is a problem with the
>>> wiring on this particular motherboard or with the ACPI _PRW methods
>>> (or the way Linux interprets them) in this firmware?
>>
>> If this is a motherboard issue or platform specific, do you prefer to use
>> DMI matches here?
>
> I'm not sure what the problem is yet, so let's hold off on the exact
> structure of the fix.

I think DMI table can put in e1000e driver instead of PCI quirk.

>
> If I understand correctly, e1000e wakeup works once, but doesn't work
> after that. Your lspci (from after that first wakeup, from
> https://bugzilla.kernel.org/attachment.cgi?id=280691) shows this:
>
> 00:14.0 XHC XHCI USB
> Flags: PMEClk- DSI- D1- D2- ... PME(D0-,D1-,D2-,D3hot+,D3cold+)
> Status: D3 NoSoftRst+ PME-Enable+ DSel=0 DScale=0 PME-
> 00:1f.3 HDAS audio
> Flags: PMEClk- DSI- D1- D2- ... PME(D0-,D1-,D2-,D3hot+,D3cold+)
> Status: D3 NoSoftRst+ PME-Enable+ DSel=0 DScale=0 PME-
> 00:1f.6 GLAN e1000e
> Flags: PMEClk- DSI+ D1- D2- ... PME(D0+,D1-,D2-,D3hot+,D3cold+)
> Status: D3 NoSoftRst+ PME-Enable+ DSel=0 DScale=1 PME+
>
> So the e1000e PME_Status bit is still set, which means it probably
> won't generate another PME interrupt, which would explain why wakeup
> doesn't work. To test this theory, can you try this:
>
> - sleep
> - wakeup via e1000e
> # DEV=00:1f.6
> # lspci -vvs $DEV
> # setpci -s $DEV CAP_PM+4.W
> # setpci -s $DEV CAP_PM+4.W=0x8100
> - sleep
> - attempt another wakeup via e1000e
>
> If this second wakeup works, it would suggest that PME_Status isn't
> being cleared correctly. I see code, e.g., in
> acpi_setup_gpe_for_wake(), that *looks* like it would arrange to clear
> it, but I'm not very familiar with it. Maybe there's some issue with
> multiple devices sharing an "implicit notification" situation like
> this.

The PME status is being cleared correctly.

The lspci is captured after I plugged the ethernet cable second time,
i.e. PME is set but not being woken up.

Kai-Heng

>
>> As for _PRW, it’s shared by USB controller, Audio controller and ethernet.
>> Only the ethernet (e1000e) has this issue.
>>
>> When this issue happens, the e1000e doesn’t get woken up by ethernet cable
>> plugging, but inserting a USB device or plugging audio jack can wake up all
>> three devices. So I think Linux interprets ACPI correctly here.
>>
>> Their _PRW here:
>> USB controller:
>> Scope (_SB.PCI0)
>> {
>> Device (XDCI)
>> {
>> Method (_PRW, 0, NotSerialized) // _PRW: Power Resources for Wake
>> {
>> Return (GPRW (0x6D, 0x04))
>> }
>>
>> Audio controller:
>> Scope (_SB.PCI0)
>> {
>> Device (HDAS)
>> {
>> …
>> Method (_PRW, 0, NotSerialized) // _PRW: Power Resources for Wake
>> {
>> Return (GPRW (0x6D, 0x04))
>> }
>>
>> Ethernet controller:
>> Scope (_SB.PCI0)
>> {
>> Device (GLAN)
>> {
>> …
>> Method (_PRW, 0, NotSerialized) // _PRW: Power Resources for Wake
>> {
>> Return (GPRW (0x6D, 0x04))
>> }
>> }
>> }
>>
>>
>>>
>>> Would you mind attaching a complete dmesg log and "sudo lspci -vvv"
>>> output to the bugzilla, please?
>>
>> Sure.
>>
>> Kai-Heng
>>
>>>
>>>> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
>>>> ---
>>>> drivers/pci/pci-acpi.c | 2 +-
>>>> drivers/pci/quirks.c | 8 ++++++++
>>>> include/linux/pci.h | 1 +
>>>> 3 files changed, 10 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
>>>> index e1949f7efd9c..184e2fc8a294 100644
>>>> --- a/drivers/pci/pci-acpi.c
>>>> +++ b/drivers/pci/pci-acpi.c
>>>> @@ -430,7 +430,7 @@ static void pci_acpi_wake_dev(struct acpi_device_wakeup_context *context)
>>>>
>>>> pci_dev = to_pci_dev(context->dev);
>>>>
>>>> - if (pci_dev->pme_poll)
>>>> + if (pci_dev->pme_poll && !pci_dev->unreliable_acpi_wake)
>>>> pci_dev->pme_poll = false;
>>>>
>>>> if (pci_dev->current_state == PCI_D3cold) {
>>>> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
>>>> index b0a413f3f7ca..ed4863496fa8 100644
>>>> --- a/drivers/pci/quirks.c
>>>> +++ b/drivers/pci/quirks.c
>>>> @@ -4948,6 +4948,14 @@ DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_AMD, PCI_ANY_ID,
>>>> DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID,
>>>> PCI_CLASS_MULTIMEDIA_HD_AUDIO, 8, quirk_gpu_hda);
>>>>
>>>> +static void quirk_unreliable_acpi_wake(struct pci_dev *pdev)
>>>> +{
>>>> + pci_info(pdev, "ACPI Wake unreliable, always poll PME\n");
>>>> + pdev->unreliable_acpi_wake = 1;
>>>> +}
>>>> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x15bb, quirk_unreliable_acpi_wake);
>>>> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, 0x15bd, quirk_unreliable_acpi_wake);
>>>> +
>>>> /*
>>>> * Some IDT switches incorrectly flag an ACS Source Validation error on
>>>> * completions for config read requests even though PCIe r4.0, sec
>>>> diff --git a/include/linux/pci.h b/include/linux/pci.h
>>>> index 65f1d8c2f082..d22065c1576f 100644
>>>> --- a/include/linux/pci.h
>>>> +++ b/include/linux/pci.h
>>>> @@ -331,6 +331,7 @@ struct pci_dev {
>>>> unsigned int pme_support:5; /* Bitmask of states from which PME#
>>>> can be generated */
>>>> unsigned int pme_poll:1; /* Poll device's PME status bit */
>>>> + unsigned int unreliable_acpi_wake:1; /* ACPI Wake doesn't always work */
>>>> unsigned int d1_support:1; /* Low power state D1 is supported */
>>>> unsigned int d2_support:1; /* Low power state D2 is supported */
>>>> unsigned int no_d1d2:1; /* D1 and D2 are forbidden */
>>>> --
>>>> 2.17.1