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[V2,6/8] PCI: Disable MSI for Tegra234 root ports

Message ID 20220423124858.25946-7-vidyas@nvidia.com (mailing list archive)
State Superseded
Delegated to: Bjorn Helgaas
Headers show
Series PCI: tegra: Add Tegra234 PCIe support | expand

Commit Message

Vidya Sagar April 23, 2022, 12:48 p.m. UTC 
Tegra234 PCIe rootports don't generate MSI interrupts for PME and AER
events. Since PCIe spec (Ref: r4.0 sec 6.1.4.3) doesn't support using
a mix of INTx and MSI/MSI-X, MSI needs to be disabled to avoid root
ports service drivers registering their respective ISRs with MSI interrupt
and to let only INTx be used for all events.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
V2:
* Addressed review comments from Bjorn i.e. changed the PCIe spec reference
  to a more relevant section and modified commit message accordingly

 drivers/pci/quirks.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)
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Patch

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 41aeaa235132..6ebb4301eb43 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -2709,8 +2709,8 @@  DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_NVIDIA,
 			nvenet_msi_disable);
 
 /*
- * PCIe spec r4.0 sec 7.7.1.2 and sec 7.7.2.2 say that if MSI/MSI-X is enabled,
- * then the device can't use INTx interrupts. Tegra's PCIe root ports don't
+ * PCIe spec r4.0 sec 6.1.4.3 says that if MSI/MSI-X is enabled,then the
+ * device can't use INTx interrupts. Tegra's PCIe root ports don't
  * generate MSI interrupts for PME and AER events instead only INTx interrupts
  * are generated. Though Tegra's PCIe root ports can generate MSI interrupts
  * for other events, since PCIe specification doesn't support using a mix of
@@ -2760,6 +2760,15 @@  DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_NVIDIA, 0x10e5,
 DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_NVIDIA, 0x10e6,
 			      PCI_CLASS_BRIDGE_PCI, 8,
 			      pci_quirk_nvidia_tegra_disable_rp_msi);
+DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_NVIDIA, 0x229a,
+			      PCI_CLASS_BRIDGE_PCI, 8,
+			      pci_quirk_nvidia_tegra_disable_rp_msi);
+DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_NVIDIA, 0x229c,
+			      PCI_CLASS_BRIDGE_PCI, 8,
+			      pci_quirk_nvidia_tegra_disable_rp_msi);
+DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_NVIDIA, 0x229e,
+			      PCI_CLASS_BRIDGE_PCI, 8,
+			      pci_quirk_nvidia_tegra_disable_rp_msi);
 
 /*
  * Some versions of the MCP55 bridge from Nvidia have a legacy IRQ routing