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Message-Id: <20191023214601.883-10-pierre-louis.bossart@linux.intel.com>
Date: Wed, 23 Oct 2019 16:45:52 -0500
From: Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>
To: alsa-devel@...a-project.org
Cc: linux-kernel@...r.kernel.org, tiwai@...e.de, broonie@...nel.org,
vkoul@...nel.org, gregkh@...uxfoundation.org, jank@...ence.com,
srinivas.kandagatla@...aro.org, slawomir.blauciak@...el.com,
Bard liao <yung-chuan.liao@...ux.intel.com>,
Rander Wang <rander.wang@...ux.intel.com>,
Ranjani Sridharan <ranjani.sridharan@...ux.intel.com>,
Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>,
Sanyog Kale <sanyog.r.kale@...el.com>
Subject: [PATCH 09/18] soundwire: bus: add helper to reset Slave status to UNATTACHED
When resuming, we need to re-enumerate and restart from UNATTACHED.
This will help implement a more robust state machine avoiding race
conditions on resume.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>
---
drivers/soundwire/bus.c | 24 ++++++++++++++++++++++++
drivers/soundwire/bus.h | 2 ++
2 files changed, 26 insertions(+)
diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index 0e761efd32f9..17c744c0ff4c 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -1107,3 +1107,27 @@ int sdw_handle_slave_status(struct sdw_bus *bus,
return ret;
}
EXPORT_SYMBOL(sdw_handle_slave_status);
+
+void sdw_clear_slave_status(struct sdw_bus *bus)
+{
+ struct sdw_slave *slave;
+ int i;
+
+ /* Check all non-zero devices */
+ for (i = 1; i <= SDW_MAX_DEVICES; i++) {
+ mutex_lock(&bus->bus_lock);
+ if (test_bit(i, bus->assigned) == false) {
+ mutex_unlock(&bus->bus_lock);
+ continue;
+ }
+ mutex_unlock(&bus->bus_lock);
+
+ slave = sdw_get_slave(bus, i);
+ if (!slave)
+ continue;
+
+ if (slave->status != SDW_SLAVE_UNATTACHED)
+ sdw_modify_slave_status(slave, SDW_SLAVE_UNATTACHED);
+ }
+}
+EXPORT_SYMBOL(sdw_clear_slave_status);
diff --git a/drivers/soundwire/bus.h b/drivers/soundwire/bus.h
index acb8d11a4c84..cdbd11292cc3 100644
--- a/drivers/soundwire/bus.h
+++ b/drivers/soundwire/bus.h
@@ -165,4 +165,6 @@ sdw_update(struct sdw_slave *slave, u32 addr, u8 mask, u8 val)
return sdw_write(slave, addr, tmp);
}
+void sdw_clear_slave_status(struct sdw_bus *bus);
+
#endif /* __SDW_BUS_H */
--
2.20.1
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