[OEM-OSP1-B] [PATCH 2/2] PCI: Avoid Pericom USB controller OHCI/EHCI PME# defect

[Kai-Heng Feng]

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>
---
 drivers/pci/quirks.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index fd246f0c07bc..72a7b1534f1f 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -5382,3 +5382,16 @@ 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);
-- 
2.17.1