Commit fd6a3ac8 authored by Pierre-Louis Bossart's avatar Pierre-Louis Bossart Committed by Vinod Koul
Browse files

soundwire: bus: fix device number leak on errors 



If the programming of the dev_number fails due to an IO error, a new
device_number will be assigned, resulting in a leak.

Make sure we only assign a device_number once per Slave device.

Signed-off-by: default avatarPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200113225637.17313-1-pierre-louis.bossart@linux.intel.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 78f6fdd6

drivers/soundwire/bus.c

+23 −14
Original line number Diff line number Diff line
@@ -456,9 +456,11 @@ static int sdw_get_device_num(struct sdw_slave *slave) 
static int sdw_assign_device_num(struct sdw_slave *slave)

{

	int ret, dev_num;

	bool new_device = false;



	/* check first if device number is assigned, if so reuse that */

	if (!slave->dev_num) {

		if (!slave->dev_num_sticky) {

			mutex_lock(&slave->bus->bus_lock);

			dev_num = sdw_get_device_num(slave);

			mutex_unlock(&slave->bus->bus_lock);
@@ -467,15 +469,22 @@ static int sdw_assign_device_num(struct sdw_slave *slave) 
					dev_num);

				return dev_num;

			}

			slave->dev_num = dev_num;

			slave->dev_num_sticky = dev_num;

			new_device = true;

		} else {

			slave->dev_num = slave->dev_num_sticky;

		}

	}



	if (!new_device)

		dev_info(slave->bus->dev,

			 "Slave already registered dev_num:%d\n",

			 "Slave already registered, reusing dev_num:%d\n",

			 slave->dev_num);



	/* Clear the slave->dev_num to transfer message on device 0 */

	dev_num = slave->dev_num;

	slave->dev_num = 0;

	}



	ret = sdw_write(slave, SDW_SCP_DEVNUMBER, dev_num);

	if (ret < 0) {
@@ -485,7 +494,7 @@ static int sdw_assign_device_num(struct sdw_slave *slave) 
	}



	/* After xfer of msg, restore dev_num */

	slave->dev_num = dev_num;

	slave->dev_num = slave->dev_num_sticky;



	return 0;

}

include/linux/soundwire/sdw.h

+3 −1
Original line number Diff line number Diff line
@@ -546,7 +546,8 @@ struct sdw_slave_ops { 
 * @debugfs: Slave debugfs

 * @node: node for bus list

 * @port_ready: Port ready completion flag for each Slave port

 * @dev_num: Device Number assigned by Bus

 * @dev_num: Current Device Number, values can be 0 or dev_num_sticky

 * @dev_num_sticky: one-time static Device Number assigned by Bus

 * @probed: boolean tracking driver state

 * @probe_complete: completion utility to control potential races

 * on startup between driver probe/initialization and SoundWire
@@ -575,6 +576,7 @@ struct sdw_slave { 
	struct list_head node;

	struct completion *port_ready;

	u16 dev_num;

	u16 dev_num_sticky;

	bool probed;

	struct completion probe_complete;

	struct completion enumeration_complete;