From fd6a3ac8e87cedd83d6aad4bbc2682a903fb5d01 Mon Sep 17 00:00:00 2001 From: Pierre-Louis Bossart Date: Mon, 13 Jan 2020 16:56:37 -0600 Subject: [PATCH] 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: Pierre-Louis Bossart Link: https://lore.kernel.org/r/20200113225637.17313-1-pierre-louis.bossart@linux.intel.com Signed-off-by: Vinod Koul --- drivers/soundwire/bus.c | 37 +++++++++++++++++++++++-------------- include/linux/soundwire/sdw.h | 4 +++- 2 files changed, 26 insertions(+), 15 deletions(-) diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index 66fd09e..6106577 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -456,26 +456,35 @@ err: 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) { - mutex_lock(&slave->bus->bus_lock); - dev_num = sdw_get_device_num(slave); - mutex_unlock(&slave->bus->bus_lock); - if (dev_num < 0) { - dev_err(slave->bus->dev, "Get dev_num failed: %d\n", - dev_num); - return 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); + if (dev_num < 0) { + dev_err(slave->bus->dev, "Get dev_num failed: %d\n", + 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; } - } else { + } + + 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; - } + /* 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; } diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h index b7c9eca..b451bb6 100644 --- a/include/linux/soundwire/sdw.h +++ b/include/linux/soundwire/sdw.h @@ -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; -- 2.7.4