Commit 0b1bd1e3 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

platform/x86/thinkpad_acpi: Use acpi_dev_for_each_child() 



Instead of walking the list of children of an ACPI device directly,
use acpi_dev_for_each_child() to carry out an action for all of
the given ACPI device's children.

This will help to eliminate the children list head from struct
acpi_device as it is redundant and it is used in questionable ways
in some places (in particular, locking is needed for walking the
list pointed to it safely, but it is often missing).

Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: default avatarHans de Goede <hdegoede@redhat.com>
parent a976a2ac

drivers/platform/x86/thinkpad_acpi.c

+27 −26
Original line number Diff line number Diff line
@@ -6841,46 +6841,47 @@ static const struct backlight_ops ibm_backlight_data = { 


/* --------------------------------------------------------------------- */



/*

 * Call _BCL method of video device.  On some ThinkPads this will

 * switch the firmware to the ACPI brightness control mode.

 */



static int __init tpacpi_query_bcl_levels(acpi_handle handle)

static int __init tpacpi_evaluate_bcl(struct acpi_device *adev, void *not_used)

{

	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };

	union acpi_object *obj;

	struct acpi_device *device, *child;

	acpi_status status;

	int rc;



	device = acpi_fetch_acpi_dev(handle);

	if (!device)

	status = acpi_evaluate_object(adev->handle, "_BCL", NULL, &buffer);

	if (ACPI_FAILURE(status))

		return 0;



	rc = 0;

	list_for_each_entry(child, &device->children, node) {

		acpi_status status = acpi_evaluate_object(child->handle, "_BCL",

							  NULL, &buffer);

		if (ACPI_FAILURE(status)) {

			buffer.length = ACPI_ALLOCATE_BUFFER;

			continue;

		}



		obj = (union acpi_object *)buffer.pointer;

		if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {

			pr_err("Unknown _BCL data, please report this to %s\n",

	obj = buffer.pointer;

	if (!obj || obj->type != ACPI_TYPE_PACKAGE) {

		acpi_handle_info(adev->handle,

				 "Unknown _BCL data, please report this to %s\n",

				 TPACPI_MAIL);

		rc = 0;

	} else {

		rc = obj->package.count;

	}

		break;

	}

	kfree(obj);



	kfree(buffer.pointer);

	return rc;

}



/*

 * Call _BCL method of video device.  On some ThinkPads this will

 * switch the firmware to the ACPI brightness control mode.

 */



static int __init tpacpi_query_bcl_levels(acpi_handle handle)

{

	struct acpi_device *device;



	device = acpi_fetch_acpi_dev(handle);

	if (!device)

		return 0;



	return acpi_dev_for_each_child(device, tpacpi_evaluate_bcl, NULL);

}





/*

 * Returns 0 (no ACPI _BCL or _BCL invalid), or size of brightness map