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authorKai-Heng Feng <kai.heng.feng@canonical.com>2017-06-16 17:40:54 +0800
committerBjorn Helgaas <bhelgaas@google.com>2017-06-30 11:15:08 -0500
commit0bf3730bbc41f155543fa63becb4ff436d6a00a9 (patch)
treeaf6b694bf06b9d73d45955ba34e19c1c70819032
parente60514bd4485c0c7c5a7cf779b200ce0b95c70d6 (diff)
downloadlinux-0bf3730bbc41f155543fa63becb4ff436d6a00a9.tar.gz
x86/PCI: Avoid AMD SB7xx EHCI USB wakeup defect
On an AMD Carrizo laptop, when EHCI runtime PM is enabled, EHCI ports do
not assert PME# for device plug/unplug events while in D3.

As Alan Stern points out [1], the PME signal is not enabled when controller
is in D3, therefore it's not being woken up when new devices get plugged
in.

Testing shows PME signal works when the EHCI power state is D2.

Clear the PCI_PM_CAP_PME_D3 and PCI_PM_CAP_PME_D3cold bits in
dev->pme_support to indicate the device will not assert PME# from those
states.

[1] http://lkml.kernel.org/r/Pine.LNX.4.44L0.1706121010010.2092-100000@iolanthe.rowland.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=196091
Link: https://support.amd.com/TechDocs/46837.pdf (Section 23)
Link: https://support.amd.com/TechDocs/42413.pdf (Appendix A2)
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
[bhelgaas: changelog, add parens in quirk]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
-rw-r--r--arch/x86/pci/fixup.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
index 6d52b94f4bb9..2259acdcede5 100644
--- a/arch/x86/pci/fixup.c
+++ b/arch/x86/pci/fixup.c
@@ -571,3 +571,18 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2fc0, pci_invalid_bar);
 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6f60, pci_invalid_bar);
 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fa0, pci_invalid_bar);
 DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fc0, pci_invalid_bar);
+
+/*
+ * Device [1022:7808]
+ * 23. USB Wake on Connect/Disconnect with Low Speed Devices
+ * https://support.amd.com/TechDocs/46837.pdf
+ * Appendix A2
+ * https://support.amd.com/TechDocs/42413.pdf
+ */
+static void pci_fixup_amd_ehci_pme(struct pci_dev *dev)
+{
+	dev_info(&dev->dev, "PME# does not work under D3, disabling it\n");
+	dev->pme_support &= ~((PCI_PM_CAP_PME_D3 | PCI_PM_CAP_PME_D3cold)
+		>> PCI_PM_CAP_PME_SHIFT);
+}
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_AMD, 0x7808, pci_fixup_amd_ehci_pme);