[PATCH 3.16 114/148] x86/PCI: Avoid AMD FCH XHCI USB PME# from D0 defect

[Ben Hutchings]

3.16.82-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>

commit 7e8ce0e2b036dbc6617184317983aea4f2c52099 upstream.

The AMD FCH USB XHCI Controller advertises support for generating PME#
while in D0.  When in D0, it does signal PME# for USB 3.0 connect events,
but not for USB 2.0 or USB 1.1 connect events, which means the controller
doesn't wake correctly for those events.

  00:10.0 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD] FCH USB XHCI Controller [1022:7914] (rev 20) (prog-if 30 [XHCI])
        Subsystem: Dell FCH USB XHCI Controller [1028:087e]
        Capabilities: [50] Power Management version 3
                Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+)

Clear PCI_PM_CAP_PME_D0 in dev->pme_support to indicate the device will not
assert PME# from D0 so we don't rely on it.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203673
Link: https://lore.kernel.org/r/20190902145252.32111-1-kai.heng.feng@xxxxxxxxxxxxx
Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 arch/x86/pci/fixup.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

--- a/arch/x86/pci/fixup.c
+++ b/arch/x86/pci/fixup.c
@@ -575,6 +575,17 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_IN
 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fc0, pci_invalid_bar);
 
 /*
+ * Device [1022:7914]
+ * When in D0, PME# doesn't get asserted when plugging USB 2.0 device.
+ */
+static void pci_fixup_amd_fch_xhci_pme(struct pci_dev *dev)
+{
+	dev_info(&dev->dev, "PME# does not work under D0, disabling it\n");
+	dev->pme_support &= ~(PCI_PM_CAP_PME_D0 >> PCI_PM_CAP_PME_SHIFT);
+}
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_AMD, 0x7914, pci_fixup_amd_fch_xhci_pme);
+
+/*
  * Apple MacBook Pro: Avoid [mem 0x7fa00000-0x7fbfffff]
  *
  * Using the [mem 0x7fa00000-0x7fbfffff] region, e.g., by assigning it to