In order to provide the most performance and/or compatible settings,
ensure VMD root buses observe the pcie bus tuning settings by
configuring those settings prior to adding the devices to the pcie tree.
This patch open-codes pci_rescan_bus() and configures the buses prior to
adding devices and attaching drivers.
Signed-off-by: Jon Derrick <jonathan.derrick@xxxxxxxxx>
---
drivers/pci/controller/vmd.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
index e50b0b5..818dda8 100644
--- a/drivers/pci/controller/vmd.c
+++ b/drivers/pci/controller/vmd.c
@@ -585,6 +585,7 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
LIST_HEAD(resources);
resource_size_t offset[2] = {0};
resource_size_t membar2_offset = 0x2000, busn_start = 0;
+ struct pci_bus *child;
/*
* Shadow registers may exist in certain VMD device ids which allow
@@ -712,7 +713,19 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
vmd_attach_resources(vmd);
vmd_setup_dma_ops(vmd);
dev_set_msi_domain(&vmd->bus->dev, vmd->irq_domain);
- pci_rescan_bus(vmd->bus);
+
+ pci_scan_child_bus(vmd->bus);
+ pci_assign_unassigned_bus_resources(vmd->bus);
+
+ /*
+ * VMD root buses are virtual and don't return true on pci_is_pcie()
+ * and will fail pcie_bus_configure_settings() early. It can instead be
+ * run on each of the real root ports.
+ */
+ list_for_each_entry(child, &vmd->bus->children, node)
+ pcie_bus_configure_settings(child);
+
+ pci_bus_add_devices(vmd->bus);
WARN(sysfs_create_link(&vmd->dev->dev.kobj, &vmd->bus->dev.kobj,
"domain"), "Can't create symlink to domain\n");
--
1.8.3.1
