NACK: [F/Unstable/OEM-5.6] [PATCH 2/2] PCI: Avoid Pericom USB controller OHCI/EHCI PME# defect

[Kai-Heng Feng]

> On May 20, 2020, at 15:27, Stefan Bader <stefan.bader at canonical.com> wrote:
> 
> On 18.05.20 15:16, Kai-Heng Feng wrote:
>> BugLink: https://bugs.launchpad.net/bugs/1879321
>> 
>> Both Pericom OHCI and EHCI devices advertise PME# support from all power
>> states:
>> 
>>  06:00.0 USB controller [0c03]: Pericom Semiconductor PI7C9X442SL USB OHCI Controller [12d8:400e] (rev 01) (prog-if 10 [OHCI])
>>    Subsystem: Pericom Semiconductor PI7C9X442SL USB OHCI Controller [12d8:400e]
>>    Capabilities: [80] Power Management version 3
>>      Flags: PMEClk- DSI- D1+ D2+ AuxCurrent=375mA PME(D0+,D1+,D2+,D3hot+,D3cold+)
>> 
>>  06:00.2 USB controller [0c03]: Pericom Semiconductor PI7C9X442SL USB EHCI Controller [12d8:400f] (rev 01) (prog-if 20 [EHCI])
>>    Subsystem: Pericom Semiconductor PI7C9X442SL USB EHCI Controller [12d8:400f]
>>    Capabilities: [80] Power Management version 3
>>      Flags: PMEClk- DSI- D1+ D2+ AuxCurrent=375mA PME(D0+,D1+,D2+,D3hot+,D3cold+)
>> 
>> But testing shows that it's unreliable: there is a 20% chance PME# won't be
>> asserted when a USB device is plugged.
>> 
>> Remove PME support for both devices to make USB plugging work reliably.
>> 
>> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=205981
>> Link: https://lore.kernel.org/r/20200508065343.32751-2-kai.heng.feng@canonical.com
>> Signed-off-by: Kai-Heng Feng <kai.heng.feng at canonical.com>
>> Signed-off-by: Bjorn Helgaas <bhelgaas at google.com>
>> Cc: stable at vger.kernel.org
>> (backported from commit 68f5fc4ea9ddf9f77720d568144219c4e6452cde linux-next)
>> Signed-off-by: Kai-Heng Feng <kai.heng.feng at canonical.com>
>> ---
> 
> The original patch just adds a new fixup function and declarations. Your
> backport removes apex_pci_fixup_class() without a real explanation why.

Thanks for catching this up, I'll send v2.

Kai-Heng

> 
> -Stefan
> 
>> drivers/pci/quirks.c | 14 ++++++++++----
>> 1 file changed, 10 insertions(+), 4 deletions(-)
>> 
>> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
>> index 8ee5e15445cc..423a6e76314c 100644
>> --- a/drivers/pci/quirks.c
>> +++ b/drivers/pci/quirks.c
>> @@ -5606,9 +5606,15 @@ static void pci_fixup_no_d0_pme(struct pci_dev *dev)
>> }
>> DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ASMEDIA, 0x2142, pci_fixup_no_d0_pme);
>> 
>> -static void apex_pci_fixup_class(struct pci_dev *pdev)
>> +/*
>> + * Device [12d8:0x400e] and [12d8:0x400f]
>> + * These devices advertise PME# support in all power states but don't
>> + * reliably assert it.
>> + */
>> +static void pci_fixup_no_pme(struct pci_dev *dev)
>> {
>> -	pdev->class = (PCI_CLASS_SYSTEM_OTHER << 8) | pdev->class;
>> +	pci_info(dev, "PME# is unreliable, disabling it\n");
>> +	dev->pme_support = 0;
>> }
>> -DECLARE_PCI_FIXUP_CLASS_HEADER(0x1ac1, 0x089a,
>> -			       PCI_CLASS_NOT_DEFINED, 8, apex_pci_fixup_class);
>> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_PERICOM, 0x400e, pci_fixup_no_pme);
>> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_PERICOM, 0x400f, pci_fixup_no_pme);
>> 
> 
>