amd64-agp: run fallback when no bridges found, not when driver registration fails

I think the intent was that if no bridges matched agp_amd64_pci_table[], we would fall back to checking for any bridge with the AGP capability. But in the current code, we execute the fallback path only when pci_register_driver() itself fails, which is unrelated to whether any matching devices were found. This patch counts the AGP bridges found in the probe() method and executes the fallback path when none is found. Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Airlie <airlied@redhat.com>

amd64-agp: run fallback when no bridges found, not when driver registration fails
I think the intent was that if no bridges matched agp_amd64_pci_table[], we would fall back to checking for any bridge with the AGP capability. But in the current code, we execute the fallback path only when pci_register_driver() itself fails, which is unrelated to whether any matching devices were found. This patch counts the AGP bridges found in the probe() method and executes the fallback path when none is found. Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Airlie <airlied@redhat.com>
Bjorn Helgaas · Dave Airlie
1 parent 99d32bd5c7
Showing 1 changed file with 13 additions and 2 deletions Side-by-side Diff
drivers/char/agp/amd64-agp.c
@@ -34,6 +34,7 @@
  
 static struct resource *aperture_resource;
 static int __initdata agp_try_unsupported = 1;
+static int agp_bridges_found;
  
 static void amd64_tlbflush(struct agp_memory *temp)
 {
@@ -489,6 +490,7 @@
 {
 	struct agp_bridge_data *bridge;
 	u8 cap_ptr;
+	int err;
  
 	cap_ptr = pci_find_capability(pdev, PCI_CAP_ID_AGP);
 	if (!cap_ptr)
@@ -536,7 +538,12 @@
 	}
  
 	pci_set_drvdata(pdev, bridge);
-	return agp_add_bridge(bridge);
+	err = agp_add_bridge(bridge);
+	if (err < 0)
+		return err;
+
+	agp_bridges_found++;
+	return 0;
 }
  
 static void __devexit agp_amd64_remove(struct pci_dev *pdev)
@@ -713,7 +720,11 @@
  
 	if (agp_off)
 		return -EINVAL;
-	if (pci_register_driver(&agp_amd64_pci_driver) < 0) {
+	err = pci_register_driver(&agp_amd64_pci_driver);
+	if (err < 0)
+		return err;
+
+	if (agp_bridges_found == 0) {
 		struct pci_dev *dev;
 		if (!agp_try_unsupported && !agp_try_unsupported_boot) {
 			printk(KERN_INFO PFX "No supported AGP bridge found.\n");
...	...	@@ -34,6 +34,7 @@
34	34
35	35	static struct resource *aperture_resource;
36	36	static int __initdata agp_try_unsupported = 1;
	37	+static int agp_bridges_found;
37	38
38	39	static void amd64_tlbflush(struct agp_memory *temp)
39	40	{
...	...	@@ -489,6 +490,7 @@
489	490	{
490	491	struct agp_bridge_data *bridge;
491	492	u8 cap_ptr;
	493	+ int err;
492	494
493	495	cap_ptr = pci_find_capability(pdev, PCI_CAP_ID_AGP);
494	496	if (!cap_ptr)
...	...	@@ -536,7 +538,12 @@
536	538	}
537	539
538	540	pci_set_drvdata(pdev, bridge);
539		- return agp_add_bridge(bridge);
	541	+ err = agp_add_bridge(bridge);
	542	+ if (err < 0)
	543	+ return err;
	544	+
	545	+ agp_bridges_found++;
	546	+ return 0;
540	547	}
541	548
542	549	static void __devexit agp_amd64_remove(struct pci_dev *pdev)
...	...	@@ -713,7 +720,11 @@
713	720
714	721	if (agp_off)
715	722	return -EINVAL;
716		- if (pci_register_driver(&agp_amd64_pci_driver) < 0) {
	723	+ err = pci_register_driver(&agp_amd64_pci_driver);
	724	+ if (err < 0)
	725	+ return err;
	726	+
	727	+ if (agp_bridges_found == 0) {
717	728	struct pci_dev *dev;
718	729	if (!agp_try_unsupported && !agp_try_unsupported_boot) {
719	730	printk(KERN_INFO PFX "No supported AGP bridge found.\n");