Commit 68f5fc4e authored May 08, 2020 by Kai-Heng Feng Committed by Bjorn Helgaas May 08, 2020

PCI: Avoid Pericom USB controller OHCI/EHCI PME# defect

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@canonical.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org

parent 62a7f300

drivers/pci/quirks.c

+13 −0

Original line number	Diff line number	Diff line
		@@ -5567,3 +5567,16 @@ static void pci_fixup_no_d0_pme(struct pci_dev *dev)
		dev->pme_support &= ~(PCI_PM_CAP_PME_D0 >> PCI_PM_CAP_PME_SHIFT);
		}
		DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ASMEDIA, 0x2142, pci_fixup_no_d0_pme);

		/*
		* 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)
		{
		pci_info(dev, "PME# is unreliable, disabling it\n");
		dev->pme_support = 0;
		}
		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);

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