On 9/7/22 12:14, Richard Fitzgerald wrote:
When the bus manager is removed sdw_bus_master_delete() should not be deleting the struct sdw_slave objects until the bus manager has been stopped. The first step of removing child drivers should only be calling device_unregister() on the child. The counterpart to sdw_drv_probe() is sdw_drv_remove(), not sdw_delete_slave().
The sdw_slave objects are created by the bus manager probe() from ACPI/DT information. They are not created when a child driver probes so should not be deleted by a child driver remove.
Change-Id: I25cc145df12fdc7c126f8f594a5f76eedce25488
spurious Change-Id
Signed-off-by: Richard Fitzgerald rf@opensource.cirrus.com
drivers/soundwire/bus.c | 30 ++++++++++++++++++++++++++---- drivers/soundwire/slave.c | 21 +++++++++++++++++---- 2 files changed, 43 insertions(+), 8 deletions(-)
diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index 1327a312be86..5533eb589286 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -146,9 +146,8 @@ int sdw_bus_master_add(struct sdw_bus *bus, struct device *parent, } EXPORT_SYMBOL(sdw_bus_master_add);
-static int sdw_delete_slave(struct device *dev, void *data) +static int sdw_delete_slave(struct sdw_slave *slave) {
struct sdw_slave *slave = dev_to_sdw_dev(dev); struct sdw_bus *bus = slave->bus;
sdw_slave_debugfs_exit(slave);
@@ -163,7 +162,24 @@ static int sdw_delete_slave(struct device *dev, void *data) list_del_init(&slave->node); mutex_unlock(&bus->bus_lock);
- mutex_destroy(&slave->sdw_dev_lock);
- kfree(slave);
- return 0;
+}
+static int sdw_remove_child(struct device *dev, void *data) +{
- /*
* Do not remove the struct sdw_slave yet. This is created by* the bus manager probe() from ACPI information and used by the* bus manager to hold status of each peripheral. Its lifetime* is that of the bus manager.*/- /* This will call sdw_drv_remove() */ device_unregister(dev);
- return 0;
}
@@ -171,16 +187,22 @@ static int sdw_delete_slave(struct device *dev, void *data)
- sdw_bus_master_delete() - delete the bus master instance
- @bus: bus to be deleted
- Remove the instance, delete the child devices.
*/
- Remove the child devices, remove the master instance.
void sdw_bus_master_delete(struct sdw_bus *bus) {
- device_for_each_child(bus->dev, NULL, sdw_delete_slave);
struct sdw_slave *slave, *tmp;
device_for_each_child(bus->dev, NULL, sdw_remove_child);
/* Children have been removed so it is now safe for the bus to stop */ if (bus->ops->remove) bus->ops->remove(bus);
/* Now the bus is stopped it is safe to free things */
list_for_each_entry_safe(slave, tmp, &bus->slaves, node)
sdw_delete_slave(slave);sdw_master_device_del(bus);
sdw_bus_debugfs_exit(bus);
diff --git a/drivers/soundwire/slave.c b/drivers/soundwire/slave.c index c1c1a2ac293a..b6161d002b97 100644 --- a/drivers/soundwire/slave.c +++ b/drivers/soundwire/slave.c @@ -10,10 +10,23 @@
static void sdw_slave_release(struct device *dev) {
- struct sdw_slave *slave = dev_to_sdw_dev(dev);
- mutex_destroy(&slave->sdw_dev_lock);
- kfree(slave);
- /*
* The release() callback should not be empty* (see Documentation/core-api/kobject.rst) but the ownership* of struct sdw_slave is muddled. It is used for two separate* purposes:* 1) by the bus driver to track its own state information for* physical devices on the bus and found in ACPI/DT, whether* or not there is a child driver for it;* 2) to hold the child driver object.** The struct sdw_slave cannot be freed when the child driver* is released because it is holding info used by the bus* driver. It is freed when the bus driver is removed.** Until the ownership issue is untangled this cannot free* the struct sdw_slave object containing the child dev.*/}
struct device_type sdw_slave_type = {