[1/1] PCI: ignore failure to preallocate minimal resources to hotplug bridges

Commit Message

Ram Pai Oct. 22, 2010, 5:16 p.m. UTC

None

Patch

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 66cb8f4..3bbc427 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -412,14 +412,14 @@  static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size)
 {
 	struct pci_dev *dev;
 	struct resource *b_res = find_free_bus_resource(bus, IORESOURCE_IO);
-	unsigned long size = 0, size1 = 0, old_size;
+	unsigned long size = 0, size1 = 0, old_size, dev_present=0;
 
 	if (!b_res)
  		return;
 
 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		int i;
-
+		dev_present=1;
 		for (i = 0; i < PCI_NUM_RESOURCES; i++) {
 			struct resource *r = &dev->resource[i];
 			unsigned long r_size;
@@ -460,6 +460,12 @@  static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size)
 	b_res->start = 4096;
 	b_res->end = b_res->start + size - 1;
 	b_res->flags |= IORESOURCE_STARTALIGN;
+
+	/* if no devices are behind this bus, inform
+	 * resource-allocater to try hard but not to worry
+	 * if allocations fail 
+	 */
+	b_res->flags |= (!dev_present) ? IORESOURCE_IGNORE_FAIL : 0;
 }
 
 /* Calculate the size of the bus and minimal alignment which
@@ -470,7 +476,7 @@  static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
 	struct pci_dev *dev;
 	resource_size_t min_align, align, size, old_size;
 	resource_size_t aligns[12];	/* Alignments from 1Mb to 2Gb */
-	int order, max_order;
+	int order, max_order, dev_present=0;
 	struct resource *b_res = find_free_bus_resource(bus, type);
 	unsigned int mem64_mask = 0;
 
@@ -487,6 +493,7 @@  static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		int i;
 
+		dev_present=1;
 		for (i = 0; i < PCI_NUM_RESOURCES; i++) {
 			struct resource *r = &dev->resource[i];
 			resource_size_t r_size;
@@ -550,6 +557,13 @@  static int pbus_size_mem(struct pci_bus *bus, unsigned long mask,
 	b_res->end = size + min_align - 1;
 	b_res->flags |= IORESOURCE_STARTALIGN;
 	b_res->flags |= mem64_mask;
+
+	/* if no devices are behind this bus, inform
+	 * resource-allocater to try hard but not to worry
+	 * if allocations fail 
+	 */
+	b_res->flags |= (!dev_present) ? IORESOURCE_IGNORE_FAIL : 0;
+
 	return 1;
 }
 
diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index 2aaa131..a8ce953 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -210,7 +210,8 @@  int pci_assign_resource(struct pci_dev *dev, int resno)
 	if (!align) {
 		dev_info(&dev->dev, "BAR %d: can't assign %pR "
 			 "(bogus alignment)\n", resno, res);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto out;
 	}
 
 	bus = dev->bus;
@@ -225,6 +226,10 @@  int pci_assign_resource(struct pci_dev *dev, int resno)
 	}
 
 	if (ret) {
+		if (res->flags & IORESOURCE_IGNORE_FAIL) {
+			ret = 0;
+			goto out;
+		}
 		if (res->flags & IORESOURCE_MEM)
 			if (res->flags & IORESOURCE_PREFETCH)
 				type = "mem pref";
@@ -239,6 +244,8 @@  int pci_assign_resource(struct pci_dev *dev, int resno)
 			 resno, type, (unsigned long long) resource_size(res));
 	}
 
+out:
+	res->flags &= ~IORESOURCE_IGNORE_FAIL;
 	return ret;
 }
 
diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index b227902..941624b 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -49,6 +49,7 @@  struct resource_list {
 
 #define IORESOURCE_SIZEALIGN	0x00040000	/* size indicates alignment */
 #define IORESOURCE_STARTALIGN	0x00080000	/* start field is alignment */
+#define IORESOURCE_IGNORE_FAIL	0x00800000 	/* IGNORE if allocation fail*/
 
 #define IORESOURCE_MEM_64	0x00100000
 #define IORESOURCE_WINDOW	0x00200000	/* forwarded by bridge */