[PATCH v6 02/30] PCI: Enable bridge's I/O and MEM access for hotplugged devices

Sergey Miroshnichenko s.miroshnichenko at yadro.com
Fri Oct 25 04:12:00 AEDT 2019


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.

Originally these bits were set by the pci_enable_device_flags() only, which
exits early if the bridge is already pci_is_enabled(). So if the bridge was
empty initially (an edge case), then hotplugged devices fail to IO/MEM.

Signed-off-by: Sergey Miroshnichenko <s.miroshnichenko at 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 44d0d12c80cf..e85dc63c73fd 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1650,6 +1650,14 @@ 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);
-- 
2.23.0



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