PCI: make pci_set_mwi a dummy for PCIe devices

Message ID 0599e4ea-55ce-9aba-d5af-1625a3db0701@gmail.com
State New
Delegated to: Bjorn Helgaas
Headers show
Series
  • PCI: make pci_set_mwi a dummy for PCIe devices
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Commit Message

Heiner Kallweit Oct. 21, 2018, 3:06 p.m.
Memory-Write-Invalidate isn't applicable for PCIe devices, therefore
make the MWI functions a dummy and don't even write to the (dummy)
PCI config space registers.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 drivers/pci/pci.c | 6 ++++++
 1 file changed, 6 insertions(+)

Patch

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index d068f11d0..fb63b3d89 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4137,6 +4137,9 @@  int pci_set_mwi(struct pci_dev *dev)
 	int rc;
 	u16 cmd;
 
+	if (pci_is_pcie(dev))
+		return 0;
+
 	rc = pci_set_cacheline_size(dev);
 	if (rc)
 		return rc;
@@ -4203,6 +4206,9 @@  void pci_clear_mwi(struct pci_dev *dev)
 #ifndef PCI_DISABLE_MWI
 	u16 cmd;
 
+	if (pci_is_pcie(dev))
+		return;
+
 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
 	if (cmd & PCI_COMMAND_INVALIDATE) {
 		cmd &= ~PCI_COMMAND_INVALIDATE;