[PATCH V2] PCI/AER: Configure ECRC only AER is native

[Vidya Sagar <vidyas@nvidia.com>]

As the ECRC configuration bits are part of AER registers, configure
ECRC only if AER is natively owned by the kernel.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
---
v2:
* Updated kernel-parameters.txt document based on Bjorn's suggestion

 Documentation/admin-guide/kernel-parameters.txt | 4 +++-
 drivers/pci/pcie/aer.c                          | 3 +++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 426fa892d311..8f85a1230525 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4242,7 +4242,9 @@
 				specified, e.g., 12@pci:8086:9c22:103c:198f
 				for 4096-byte alignment.
 		ecrc=		Enable/disable PCIe ECRC (transaction layer
-				end-to-end CRC checking).
+				end-to-end CRC checking). Only effective if
+				OS has native AER control (either granted by
+				ACPI _OSC or forced via "pcie_ports=native")
 				bios: Use BIOS/firmware settings. This is the
 				the default.
 				off: Turn ECRC off
diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index e2d8a74f83c3..730b47bdcdef 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -184,6 +184,9 @@ static int disable_ecrc_checking(struct pci_dev *dev)
  */
 void pcie_set_ecrc_checking(struct pci_dev *dev)
 {
+	if (!pcie_aer_is_native(dev))
+		return;
+
 	switch (ecrc_policy) {
 	case ECRC_POLICY_DEFAULT:
 		return;
-- 
2.17.1