[alsa-devel] [PATCH v3 01/10] ACPI / utils: Introduce acpi_dev_get_first_match_dev() helper

[Andy Shevchenko]

The acpi_dev_get_first_match_name() is missing put_device() call
and thus keeping reference counting unbalanced.

In order to fix the issue introduce a new helper to convert existing users
one-by-one to a better API. And then remove the old one.

Signed-off-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede at redhat.com>
---
 drivers/acpi/utils.c    | 24 ++++++++++++++++++++++--
 include/acpi/acpi_bus.h |  3 +++
 include/linux/acpi.h    |  6 ++++++
 3 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
index c4b06cc075f9..5a2bae2b6c3a 100644
--- a/drivers/acpi/utils.c
+++ b/drivers/acpi/utils.c
@@ -739,6 +739,7 @@ EXPORT_SYMBOL(acpi_dev_found);
 
 struct acpi_dev_match_info {
 	const char *dev_name;
+	struct acpi_device *adev;
 	struct acpi_device_id hid[2];
 	const char *uid;
 	s64 hrv;
@@ -759,6 +760,7 @@ static int acpi_dev_match_cb(struct device *dev, void *data)
 		return 0;
 
 	match->dev_name = acpi_dev_name(adev);
+	match->adev = adev;
 
 	if (match->hrv == -1)
 		return 1;
@@ -806,16 +808,34 @@ bool acpi_dev_present(const char *hid, const char *uid, s64 hrv)
 EXPORT_SYMBOL(acpi_dev_present);
 
 /**
- * acpi_dev_get_first_match_name - Return name of first match of ACPI device
+ * acpi_dev_get_first_match_dev - Return the first match of ACPI device
  * @hid: Hardware ID of the device.
  * @uid: Unique ID of the device, pass NULL to not check _UID
  * @hrv: Hardware Revision of the device, pass -1 to not check _HRV
  *
- * Return device name if a matching device was present
+ * Return the first match of ACPI device if a matching device was present
  * at the moment of invocation, or NULL otherwise.
  *
+ * The caller is responsible to call put_device() on the returned device.
+ *
  * See additional information in acpi_dev_present() as well.
  */
+struct acpi_device *
+acpi_dev_get_first_match_dev(const char *hid, const char *uid, s64 hrv)
+{
+	struct acpi_dev_match_info match = {};
+	struct device *dev;
+
+	strlcpy(match.hid[0].id, hid, sizeof(match.hid[0].id));
+	match.uid = uid;
+	match.hrv = hrv;
+
+	dev = bus_find_device(&acpi_bus_type, NULL, &match, acpi_dev_match_cb);
+	return dev ? match.adev : NULL;
+}
+EXPORT_SYMBOL(acpi_dev_get_first_match_dev);
+
+/* DEPRECATED, use acpi_dev_get_first_match_dev() instead */
 const char *
 acpi_dev_get_first_match_name(const char *hid, const char *uid, s64 hrv)
 {
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 0300374101cd..2063e9e2f384 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -91,6 +91,9 @@ acpi_evaluate_dsm_typed(acpi_handle handle, const guid_t *guid, u64 rev,
 bool acpi_dev_found(const char *hid);
 bool acpi_dev_present(const char *hid, const char *uid, s64 hrv);
 
+struct acpi_device *
+acpi_dev_get_first_match_dev(const char *hid, const char *uid, s64 hrv);
+
 const char *
 acpi_dev_get_first_match_name(const char *hid, const char *uid, s64 hrv);
 
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index d5dcebd7aad3..3e1d16b00513 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -669,6 +669,12 @@ static inline bool acpi_dev_present(const char *hid, const char *uid, s64 hrv)
 	return false;
 }
 
+static inline struct acpi_device *
+acpi_dev_get_first_match_dev(const char *hid, const char *uid, s64 hrv)
+{
+	return NULL;
+}
+
 static inline const char *
 acpi_dev_get_first_match_name(const char *hid, const char *uid, s64 hrv)
 {
-- 
2.20.1