We need an async mechanism to prevent access to Slaves that are not
fully-enumerated.
init_completion() will be invoked when the Slave becomes UNATTACHED,
and complete() will be invoked when the state become ATTACHED. Any
read/write before this status change will be delayed with a
wait_for_completion().
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
---
include/linux/soundwire/sdw.h | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h
index a381a596212b..2c6688eb4c09 100644
--- a/include/linux/soundwire/sdw.h
+++ b/include/linux/soundwire/sdw.h
@@ -549,6 +549,9 @@ struct sdw_slave_ops {
* @probe_complete: completion utility to control potential races
* on startup between driver probe/initialization and SoundWire
* Slave state changes/imp-def interrupts
+ * @enumeration_complete: completion utility to control potential races
+ * on startup between device enumeration and read/write access to the
+ * Slave device
*/
struct sdw_slave {
struct sdw_slave_id id;
@@ -565,6 +568,7 @@ struct sdw_slave {
u16 dev_num;
bool probed;
struct completion probe_complete;
+ struct completion enumeration_complete;
};
#define dev_to_sdw_dev(_dev) container_of(_dev, struct sdw_slave, dev)
--
2.20.1
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