[PATCH] pci: remove warning messages

[firefly-linux-kernel-4.4.55.git] / drivers / pci / search.c

diff --git a/drivers/pci/search.c b/drivers/pci/search.c
index 2f13eba5d5aebf9c7a9f0930cbc1022bde441f75..b2653c4afe9e69212f8923df0574561cc049eaef 100644 (file)
--- a/drivers/pci/search.c
+++ b/drivers/pci/search.c
@@ -193,6 +193,15 @@ static struct pci_dev * pci_find_subsys(unsigned int vendor,
        struct pci_dev *dev;
 
        WARN_ON(in_interrupt());
+
+       /*
+        * pci_find_subsys() can be called on the ide_setup() path, super-early
+        * in boot.  But the down_read() will enable local interrupts, which
+        * can cause some machines to crash.  So here we detect and flag that
+        * situation and bail out early.
+        */
+       if (unlikely(list_empty(&pci_devices)))
+               return NULL;
        down_read(&pci_bus_sem);
        n = from ? from->global_list.next : pci_devices.next;
 
@@ -259,6 +268,15 @@ pci_get_subsys(unsigned int vendor, unsigned int device,
        struct pci_dev *dev;
 
        WARN_ON(in_interrupt());
+
+       /*
+        * pci_get_subsys() can potentially be called by drivers super-early
+        * in boot.  But the down_read() will enable local interrupts, which
+        * can cause some machines to crash.  So here we detect and flag that
+        * situation and bail out early.
+        */
+       if (unlikely(list_empty(&pci_devices)))
+               return NULL;
        down_read(&pci_bus_sem);
        n = from ? from->global_list.next : pci_devices.next;
 
@@ -413,6 +431,24 @@ exit:
        return dev;
 }
 
+const struct pci_device_id *pci_find_present(const struct pci_device_id *ids)
+{
+       struct pci_dev *dev;
+       const struct pci_device_id *found = NULL;
+
+       WARN_ON(in_interrupt());
+       down_read(&pci_bus_sem);
+       while (ids->vendor || ids->subvendor || ids->class_mask) {
+               list_for_each_entry(dev, &pci_devices, global_list) {
+                       if ((found = pci_match_one_device(ids, dev)) != NULL)
+                               break;
+               }
+               ids++;
+       }
+       up_read(&pci_bus_sem);
+       return found;
+}
+
 /**
  * pci_dev_present - Returns 1 if device matching the device list is present, 0 if not.
  * @ids: A pointer to a null terminated list of struct pci_device_id structures
@@ -426,25 +462,11 @@ exit:
  */
 int pci_dev_present(const struct pci_device_id *ids)
 {
-       struct pci_dev *dev;
-       int found = 0;
-
-       WARN_ON(in_interrupt());
-       down_read(&pci_bus_sem);
-       while (ids->vendor || ids->subvendor || ids->class_mask) {
-               list_for_each_entry(dev, &pci_devices, global_list) {
-                       if (pci_match_one_device(ids, dev)) {
-                               found = 1;
-                               goto exit;
-                       }
-               }
-               ids++;
-       }
-exit:
-       up_read(&pci_bus_sem);
-       return found;
+       return pci_find_present(ids) == NULL ? 0 : 1;
 }
+
 EXPORT_SYMBOL(pci_dev_present);
+EXPORT_SYMBOL(pci_find_present);
 
 EXPORT_SYMBOL(pci_find_device);
 EXPORT_SYMBOL(pci_find_device_reverse);