[PATCH 2/2] PCI/ASPM: Avoid L0s and L1 on Freescale Root Ports

[Bjorn Helgaas <helgaas@kernel.org>]

From: Bjorn Helgaas <bhelgaas@google.com>

Christian reported that f3ac2ff14834 ("PCI/ASPM: Enable all ClockPM and
ASPM states for devicetree platforms") broke booting on the A-EON X5000.

Fixes: f3ac2ff14834 ("PCI/ASPM: Enable all ClockPM and ASPM states for devicetree platforms")
Fixes: df5192d9bb0e ("PCI/ASPM: Enable only L0s and L1 for devicetree platforms"
)
Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Link: https://lore.kernel.org/r/db5c95a1-cf3e-46f9-8045-a1b04908051a@xenosoft.de
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
---
 drivers/pci/quirks.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 214ed060ca1b..44e780718953 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -2525,6 +2525,18 @@ static void quirk_disable_aspm_l0s_l1(struct pci_dev *dev)
  */
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ASMEDIA, 0x1080, quirk_disable_aspm_l0s_l1);
 
+/*
+ * Remove ASPM L0s and L1 support from cached copy of Link Capabilities so
+ * aspm.c won't try to enable them.
+ */
+static void quirk_disable_aspm_l0s_l1_cap(struct pci_dev *dev)
+{
+	dev->lnkcap &= ~PCI_EXP_LNKCAP_ASPM_L0S;
+	dev->lnkcap &= ~PCI_EXP_LNKCAP_ASPM_L1;
+	pci_info(dev, "ASPM: L0s L1 removed from Link Capabilities to work around device defect\n");
+}
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_FREESCALE, 0x0451, quirk_disable_aspm_l0s_l1_cap);
+
 /*
  * Some Pericom PCIe-to-PCI bridges in reverse mode need the PCIe Retrain
  * Link bit cleared after starting the link retrain process to allow this
-- 
2.43.0