ACPI / scan: Simplify acpi_match_device()

Redefine acpi_companion_match() to return an ACPI device object
pointer instead of a bool and use it to remove some redundant code
from acpi_match_device().

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 99f97ac..b4d5549 100644 (file)
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -194,7 +194,8 @@ static int create_modalias(struct acpi_device *acpi_dev, char *modalias,
  *
  * Check if the given device has an ACPI companion and if that companion has
  * a valid list of PNP IDs, and if the device is the first (primary) physical
- * device associated with it.
+ * device associated with it.  Return the companion pointer if that's the case
+ * or NULL otherwise.
  *
  * If multiple physical devices are attached to a single ACPI companion, we need
  * to be careful.  The usage scenario for this kind of relationship is that all
@@ -208,31 +209,31 @@ static int create_modalias(struct acpi_device *acpi_dev, char *modalias,
  * resources available from it but they will be matched normally using functions
  * provided by their bus types (and analogously for their modalias).
  */
-static bool acpi_companion_match(const struct device *dev)
+static struct acpi_device *acpi_companion_match(const struct device *dev)
 {
        struct acpi_device *adev;
-       bool ret;
 
        adev = ACPI_COMPANION(dev);
        if (!adev)
-               return false;
+               return NULL;
 
        if (list_empty(&adev->pnp.ids))
-               return false;
+               return NULL;
 
        mutex_lock(&adev->physical_node_lock);
        if (list_empty(&adev->physical_node_list)) {
-               ret = false;
+               adev = NULL;
        } else {
                const struct acpi_device_physical_node *node;
 
                node = list_first_entry(&adev->physical_node_list,
                                        struct acpi_device_physical_node, node);
-               ret = node->dev == dev;
+               if (node->dev != dev)
+                       adev = NULL;
        }
        mutex_unlock(&adev->physical_node_lock);
 
-       return ret;
+       return adev;
 }
 
 /*
@@ -904,7 +905,7 @@ static const struct acpi_device_id *__acpi_match_device(
         * If the device is not present, it is unnecessary to load device
         * driver for it.
         */
-       if (!device->status.present)
+       if (!device || !device->status.present)
                return NULL;
 
        for (id = ids; id->id[0]; id++)
@@ -929,16 +930,7 @@ static const struct acpi_device_id *__acpi_match_device(
 const struct acpi_device_id *acpi_match_device(const struct acpi_device_id *ids,
                                               const struct device *dev)
 {
-       struct acpi_device *adev;
-       acpi_handle handle = ACPI_HANDLE(dev);
-
-       if (!ids || !handle || acpi_bus_get_device(handle, &adev))
-               return NULL;
-
-       if (!acpi_companion_match(dev))
-               return NULL;
-
-       return __acpi_match_device(adev, ids);
+       return __acpi_match_device(acpi_companion_match(dev), ids);
 }
 EXPORT_SYMBOL_GPL(acpi_match_device);