diff options
| author | Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> | 2020-01-15 03:08:36 +0300 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2020-02-25 13:27:02 +0300 |
| commit | fb9469e54fa7a7b6a8137c40ae66c41b8d0ab175 (patch) | |
| tree | cad02606cea942f7755c18e20e5ac5e4a937c4ea /drivers/soundwire | |
| parent | 2140b66b5d3ecf6c7c0fa9dc5eebb41855765ace (diff) | |
| download | linux-fb9469e54fa7a7b6a8137c40ae66c41b8d0ab175.tar.xz | |
soundwire: bus: fix race condition with enumeration_complete signaling
This patch adds the signaling needed for Slave drivers to wait until
the enumeration completes so that race conditions when issuing
read/write commands are avoided. The calls for wait_for_completion()
will be added in codec drivers in follow-up patches.
The order between init_completion() and complete() is deterministic,
the Slave is marked as UNATTACHED either during a Master-initiated
HardReset, or when the hardware detects the Slave no longer reports as
ATTACHED.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200115000844.14695-3-pierre-louis.bossart@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/soundwire')
| -rw-r--r-- | drivers/soundwire/bus.c | 20 | ||||
| -rw-r--r-- | drivers/soundwire/slave.c | 1 |
2 files changed, 21 insertions, 0 deletions
diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index 4980dfd6f3a3..a2267c3a1d2d 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -610,6 +610,26 @@ static void sdw_modify_slave_status(struct sdw_slave *slave, enum sdw_slave_status status) { mutex_lock(&slave->bus->bus_lock); + + dev_vdbg(&slave->dev, + "%s: changing status slave %d status %d new status %d\n", + __func__, slave->dev_num, slave->status, status); + + if (status == SDW_SLAVE_UNATTACHED) { + dev_dbg(&slave->dev, + "%s: initializing completion for Slave %d\n", + __func__, slave->dev_num); + + init_completion(&slave->enumeration_complete); + + } else if ((status == SDW_SLAVE_ATTACHED) && + (slave->status == SDW_SLAVE_UNATTACHED)) { + dev_dbg(&slave->dev, + "%s: signaling completion for Slave %d\n", + __func__, slave->dev_num); + + complete(&slave->enumeration_complete); + } slave->status = status; mutex_unlock(&slave->bus->bus_lock); } diff --git a/drivers/soundwire/slave.c b/drivers/soundwire/slave.c index 08db0488e02d..e767a78066ee 100644 --- a/drivers/soundwire/slave.c +++ b/drivers/soundwire/slave.c @@ -46,6 +46,7 @@ static int sdw_slave_add(struct sdw_bus *bus, slave->dev.of_node = of_node_get(to_of_node(fwnode)); slave->bus = bus; slave->status = SDW_SLAVE_UNATTACHED; + init_completion(&slave->enumeration_complete); slave->dev_num = 0; init_completion(&slave->probe_complete); slave->probed = false; |