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

Message ID 20200521052952.19762-4-kai.heng.feng@canonical.com
State New
Headers show
Series None | expand

Commit Message

Kai-Heng Feng May 21, 2020, 5:29 a.m. UTC
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@canonical.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org
(backported from commit 68f5fc4ea9ddf9f77720d568144219c4e6452cde linux-next)
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
 drivers/pci/quirks.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)
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Patch

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 8ee5e15445cc..9c68b33a8ded 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -5612,3 +5612,16 @@  static void apex_pci_fixup_class(struct pci_dev *pdev)
 }
 DECLARE_PCI_FIXUP_CLASS_HEADER(0x1ac1, 0x089a,
 			       PCI_CLASS_NOT_DEFINED, 8, apex_pci_fixup_class);
+
+/*
+ * 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);