[PATCH 4.14 148/190] PCI: Disable MSI for Freescale Layerscape PCIe RC mode

From: Greg Kroah-Hartman
Date: Fri Jun 19 2020 - 12:34:15 EST


From: Hou Zhiqiang <Zhiqiang.Hou@xxxxxxx>

[ Upstream commit 06dc4ee54e306eff61cbdac3593b42b09f618103 ]

The Freescale PCIe controller advertises the MSI/MSI-X capability in both
RC and Endpoint mode, but in RC mode it doesn't support MSI/MSI-X by
itself; it can only transfer MSI/MSI-X from downstream devices.

Add a quirk to prevent use of MSI/MSI-X in RC mode.

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@xxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Acked-by: Minghuan Lian <minghuan.Lian@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/pci/quirks.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index e7ed051ec125..c751f2f81142 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -4912,3 +4912,11 @@ static void quirk_no_ats(struct pci_dev *pdev)
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x98e4, quirk_no_ats);
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x6900, quirk_no_ats);
#endif /* CONFIG_PCI_ATS */
+
+/* Freescale PCIe doesn't support MSI in RC mode */
+static void quirk_fsl_no_msi(struct pci_dev *pdev)
+{
+ if (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT)
+ pdev->no_msi = 1;
+}
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_FREESCALE, PCI_ANY_ID, quirk_fsl_no_msi);
--
2.25.1