PCI: Delay enabling bridges until they're needed
We currently enable PCI bridges after scanning a bus and assigning
resources. This is often done in arch code.
This patch changes this so we don't enable a bridge until necessary, i.e.,
until we enable a PCI device behind the bridge. We do this in the generic
pci_enable_device() path, so this also removes the arch-specific code to
enable bridges.
[bhelgaas: changelog]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index e37fea6..44a1a8a 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1145,6 +1145,24 @@
return 0;
}
+static void pci_enable_bridge(struct pci_dev *dev)
+{
+ int retval;
+
+ if (!dev)
+ return;
+
+ pci_enable_bridge(dev->bus->self);
+
+ if (pci_is_enabled(dev))
+ return;
+ retval = pci_enable_device(dev);
+ if (retval)
+ dev_err(&dev->dev, "Error enabling bridge (%d), continuing\n",
+ retval);
+ pci_set_master(dev);
+}
+
static int pci_enable_device_flags(struct pci_dev *dev, unsigned long flags)
{
int err;
@@ -1165,6 +1183,8 @@
if (atomic_inc_return(&dev->enable_cnt) > 1)
return 0; /* already enabled */
+ pci_enable_bridge(dev->bus->self);
+
/* only skip sriov related */
for (i = 0; i <= PCI_ROM_RESOURCE; i++)
if (dev->resource[i].flags & flags)