[PATCH 3/7] soundwire: slave: add first_interrupt_done status

[Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx>]

From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>

Some Slaves report incorrect information in their interrupt status
registers after a master/bus reset, track the initial interrupt
handling so that quirks can be introduced to filter out incorrect
information while keeping interrupts enabled in steady state.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
Reviewed-by: Kai Vehmanen <kai.vehmanen@xxxxxxxxxxxxxxx>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@xxxxxxxxxxxxxxx>
Signed-off-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx>
---
 drivers/soundwire/bus.c       | 7 ++++++-
 drivers/soundwire/slave.c     | 1 +
 include/linux/soundwire/sdw.h | 3 +++
 3 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index 9e5bcd0dd115..cddf39e3adfc 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -1472,6 +1472,9 @@ static int sdw_handle_slave_alerts(struct sdw_slave *slave)
 			goto io_err;
 		}
 
+		/* at this point all initial interrupt sources were handled */
+		slave->first_interrupt_done = true;
+
 		/*
 		 * Read status again to ensure no new interrupts arrived
 		 * while servicing interrupts.
@@ -1674,8 +1677,10 @@ void sdw_clear_slave_status(struct sdw_bus *bus, u32 request)
 		if (!slave)
 			continue;
 
-		if (slave->status != SDW_SLAVE_UNATTACHED)
+		if (slave->status != SDW_SLAVE_UNATTACHED) {
 			sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
+			slave->first_interrupt_done = false;
+		}
 
 		/* keep track of request, used in pm_runtime resume */
 		slave->unattach_request = request;
diff --git a/drivers/soundwire/slave.c b/drivers/soundwire/slave.c
index 0839445ee07b..755d43eba63b 100644
--- a/drivers/soundwire/slave.c
+++ b/drivers/soundwire/slave.c
@@ -57,6 +57,7 @@ static int sdw_slave_add(struct sdw_bus *bus,
 	slave->dev_num = 0;
 	init_completion(&slave->probe_complete);
 	slave->probed = false;
+	slave->first_interrupt_done = false;
 
 	mutex_lock(&bus->bus_lock);
 	list_add_tail(&slave->node, &bus->slaves);
diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h
index 6d91f2ca20b2..3550ab530c43 100644
--- a/include/linux/soundwire/sdw.h
+++ b/include/linux/soundwire/sdw.h
@@ -608,6 +608,8 @@ struct sdw_slave_ops {
  * between the Master suspending and the codec resuming, and make sure that
  * when the Master triggered a reset the Slave is properly enumerated and
  * initialized
+ * @first_interrupt_done: status flag tracking if the interrupt handling
+ * for a Slave happens for the first time after enumeration
  */
 struct sdw_slave {
 	struct sdw_slave_id id;
@@ -629,6 +631,7 @@ struct sdw_slave {
 	struct completion enumeration_complete;
 	struct completion initialization_complete;
 	u32 unattach_request;
+	bool first_interrupt_done;
 };
 
 #define dev_to_sdw_dev(_dev) container_of(_dev, struct sdw_slave, dev)
-- 
2.17.1