Commit 9089d1a4 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

soundwire: 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 avatarPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Tested-by: default avatarPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Acked-By: default avatarVinod Koul <vkoul@kernel.org>
parent 0b1bd1e3

drivers/soundwire/slave.c

+67 −50
Original line number Diff line number Diff line
@@ -127,71 +127,88 @@ static bool find_slave(struct sdw_bus *bus, 
	return true;

}



/*

 * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node

 * @bus: SDW bus instance

 *

 * Scans Master ACPI node for SDW child Slave devices and registers it.

 */

int sdw_acpi_find_slaves(struct sdw_bus *bus)

{

	struct acpi_device *adev, *parent;

	struct acpi_device *adev2, *parent2;



	parent = ACPI_COMPANION(bus->dev);

	if (!parent) {

		dev_err(bus->dev, "Can't find parent for acpi bind\n");

		return -ENODEV;

	}



	list_for_each_entry(adev, &parent->children, node) {

struct sdw_acpi_child_walk_data {

	struct sdw_bus *bus;

	struct acpi_device *adev;

	struct sdw_slave_id id;

		struct sdw_slave_id id2;

		bool ignore_unique_id = true;



		if (!find_slave(bus, adev, &id))

			continue;

	bool ignore_unique_id;

};



		/* brute-force O(N^2) search for duplicates */

		parent2 = parent;

		list_for_each_entry(adev2, &parent2->children, node) {

static int sdw_acpi_check_duplicate(struct acpi_device *adev, void *data)

{

	struct sdw_acpi_child_walk_data *cwd = data;

	struct sdw_bus *bus = cwd->bus;

	struct sdw_slave_id id;



			if (adev == adev2)

				continue;

	if (adev == cwd->adev)

		return 0;



			if (!find_slave(bus, adev2, &id2))

				continue;

	if (!find_slave(bus, adev, &id))

		return 0;



			if (id.sdw_version != id2.sdw_version ||

			    id.mfg_id != id2.mfg_id ||

			    id.part_id != id2.part_id ||

			    id.class_id != id2.class_id)

				continue;

	if (cwd->id.sdw_version != id.sdw_version || cwd->id.mfg_id != id.mfg_id ||

	    cwd->id.part_id != id.part_id || cwd->id.class_id != id.class_id)

		return 0;



			if (id.unique_id != id2.unique_id) {

	if (cwd->id.unique_id != id.unique_id) {

		dev_dbg(bus->dev,

			"Valid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",

					id.unique_id, id2.unique_id, id.mfg_id, id.part_id);

				ignore_unique_id = false;

			} else {

			cwd->id.unique_id, id.unique_id, cwd->id.mfg_id,

			cwd->id.part_id);

		cwd->ignore_unique_id = false;

		return 0;

	}



	dev_err(bus->dev,

		"Invalid unique IDs 0x%x 0x%x for Slave mfg_id 0x%04x, part_id 0x%04x\n",

					id.unique_id, id2.unique_id, id.mfg_id, id.part_id);

		cwd->id.unique_id, id.unique_id, cwd->id.mfg_id, cwd->id.part_id);

	return -ENODEV;

}

		}



		if (ignore_unique_id)

			id.unique_id = SDW_IGNORED_UNIQUE_ID;

static int sdw_acpi_find_one(struct acpi_device *adev, void *data)

{

	struct sdw_bus *bus = data;

	struct sdw_acpi_child_walk_data cwd = {

		.bus = bus,

		.adev = adev,

		.ignore_unique_id = true,

	};

	int ret;



	if (!find_slave(bus, adev, &cwd.id))

		return 0;



	/* Brute-force O(N^2) search for duplicates. */

	ret = acpi_dev_for_each_child(ACPI_COMPANION(bus->dev),

				      sdw_acpi_check_duplicate, &cwd);

	if (ret)

		return ret;



	if (cwd.ignore_unique_id)

		cwd.id.unique_id = SDW_IGNORED_UNIQUE_ID;



	/* Ignore errors and continue. */

	sdw_slave_add(bus, &cwd.id, acpi_fwnode_handle(adev));

	return 0;

}



/*

		 * don't error check for sdw_slave_add as we want to continue

		 * adding Slaves

 * sdw_acpi_find_slaves() - Find Slave devices in Master ACPI node

 * @bus: SDW bus instance

 *

 * Scans Master ACPI node for SDW child Slave devices and registers it.

 */

		sdw_slave_add(bus, &id, acpi_fwnode_handle(adev));

int sdw_acpi_find_slaves(struct sdw_bus *bus)

{

	struct acpi_device *parent;



	parent = ACPI_COMPANION(bus->dev);

	if (!parent) {

		dev_err(bus->dev, "Can't find parent for acpi bind\n");

		return -ENODEV;

	}



	return 0;

	return acpi_dev_for_each_child(parent, sdw_acpi_find_one, bus);

}



#endif