[PATCH v7 02/26] PCI: Enable bridge's I/O and MEM access for hotplugged devices

[Sergei Miroshnichenko <s.miroshnichenko@yadro.com>]

The PCI_COMMAND_IO and PCI_COMMAND_MEMORY bits of the bridge must be
updated not only when enabling the bridge for the first time, but also if a
hotplugged device requests these types of resources.

For example, if a bridge had all its slots empty, the IO and MEM bits will
not be set, and a hot hotplugged device will fail.

Originally these bits were set by the pci_enable_device_flags() only, which
exits early if the bridge is already pci_is_enabled(). So let's check them
again when requested.

Signed-off-by: Sergei Miroshnichenko <s.miroshnichenko@yadro.com>
---
 drivers/pci/pci.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 0366289c75e9..cb0042f28e6a 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1679,6 +1679,14 @@ static void pci_enable_bridge(struct pci_dev *dev)
 		pci_enable_bridge(bridge);
 
 	if (pci_is_enabled(dev)) {
+		int i, bars = 0;
+
+		for (i = PCI_BRIDGE_RESOURCES; i < DEVICE_COUNT_RESOURCE; i++) {
+			if (dev->resource[i].flags & (IORESOURCE_MEM | IORESOURCE_IO))
+				bars |= (1 << i);
+		}
+		do_pci_enable_device(dev, bars);
+
 		if (!dev->is_busmaster)
 			pci_set_master(dev);
 		mutex_unlock(&dev->enable_mutex);
-- 
2.24.1