[PATCH] PCI: Avoid ASMedia XHCI USB PME# from D0 defect - Kai-Heng Feng

From: Kai-Heng Feng <kai.heng.feng@canonical.com>
To: bhelgaas@google.com
Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
	Kai-Heng Feng <kai.heng.feng@canonical.com>
Subject: [PATCH] PCI: Avoid ASMedia XHCI USB PME# from D0 defect
Date: Fri, 20 Dec 2019 03:20:06 +0800	[thread overview]
Message-ID: <20191219192006.16270-1-kai.heng.feng@canonical.com> (raw)

The ASMedia USB XHCI Controller claims to support generating PME# while
in D0:

01:00.0 USB controller: ASMedia Technology Inc. Device 2142 (prog-if 30 [XHCI])
        Subsystem: SUNIX Co., Ltd. Device 312b
        Capabilities: [78] Power Management version 3
                Flags: PMEClk- DSI- D1- D2- AuxCurrent=55mA PME(D0+,D1-,D2-,D3hot-,D3cold-)
                Status: D0 NoSoftRst+ PME-Enable+ DSel=0 DScale=0 PME-

However PME# only gets asserted when plugging USB 2.0 or USB 1.1
devices, but not for USB 3.0 devices.

So remove PCI_PM_CAP_PME_D0 to avoid using PME under D0.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=205919
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
 drivers/pci/quirks.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 79379b4c9d7a..24c71555dc77 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -5436,3 +5436,14 @@ static void quirk_reset_lenovo_thinkpad_p50_nvgpu(struct pci_dev *pdev)
 DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_NVIDIA, 0x13b1,
 			      PCI_CLASS_DISPLAY_VGA, 8,
 			      quirk_reset_lenovo_thinkpad_p50_nvgpu);
+
+/*
+ * Device [1b21:2142]
+ * When in D0, PME# doesn't get asserted when plugging USB 3.0 device.
+ */
+static void pci_fixup_no_d0_pme(struct pci_dev *dev)
+{
+	pci_info(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_ASMEDIA, 0x2142, pci_fixup_no_d0_pme);
-- 
2.17.1

