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authorPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>2020-01-14 18:08:37 -0600
committerVinod Koul <vkoul@kernel.org>2020-02-25 15:57:02 +0530
commita90def0681270eb58496825b8861aa9ffca6abce (patch)
tree47fa647d65057324917b5aa65f23a6749d7d720d /drivers/soundwire
parentfb9469e54fa7a7b6a8137c40ae66c41b8d0ab175 (diff)
downloadlinux-a90def0681270eb58496825b8861aa9ffca6abce.tar.bz2
soundwire: bus: fix race condition with initialization_complete signaling
Waiting for the enumeration to be complete may not be enough for a Slave driver, there is a possible race condition between resume operations and initializations handled in an interrupt thread, which can results in settings not being fully restored after system or pm_runtime resume. This patch builds on the changes added for enumeration_complete, init_completion() is called when the Slave device becomes UNATTACHED, as done with enumeration_complete. The difference with the enumeration_complete case is that complete() is signaled after the Slave device is fully initialized after the .update_status() callback is called. A Slave device driver can decide to wait on either of the two complete() cases, depending on its initialization code and requirements. Signed-off-by: Rander Wang <rander.wang@linux.intel.com> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Link: https://lore.kernel.org/r/20200115000844.14695-4-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.c8
-rw-r--r--drivers/soundwire/slave.c1
2 files changed, 9 insertions, 0 deletions
diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index a2267c3a1d2d..ea04cf5f5bdc 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -621,6 +621,7 @@ static void sdw_modify_slave_status(struct sdw_slave *slave,
__func__, slave->dev_num);
init_completion(&slave->enumeration_complete);
+ init_completion(&slave->initialization_complete);
} else if ((status == SDW_SLAVE_ATTACHED) &&
(slave->status == SDW_SLAVE_UNATTACHED)) {
@@ -1025,6 +1026,7 @@ int sdw_handle_slave_status(struct sdw_bus *bus,
{
enum sdw_slave_status prev_status;
struct sdw_slave *slave;
+ bool attached_initializing;
int i, ret = 0;
/* first check if any Slaves fell off the bus */
@@ -1070,6 +1072,8 @@ int sdw_handle_slave_status(struct sdw_bus *bus,
if (!slave)
continue;
+ attached_initializing = false;
+
switch (status[i]) {
case SDW_SLAVE_UNATTACHED:
if (slave->status == SDW_SLAVE_UNATTACHED)
@@ -1096,6 +1100,8 @@ int sdw_handle_slave_status(struct sdw_bus *bus,
if (prev_status == SDW_SLAVE_ALERT)
break;
+ attached_initializing = true;
+
ret = sdw_initialize_slave(slave);
if (ret)
dev_err(bus->dev,
@@ -1114,6 +1120,8 @@ int sdw_handle_slave_status(struct sdw_bus *bus,
if (ret)
dev_err(slave->bus->dev,
"Update Slave status failed:%d\n", ret);
+ if (attached_initializing)
+ complete(&slave->initialization_complete);
}
return ret;
diff --git a/drivers/soundwire/slave.c b/drivers/soundwire/slave.c
index e767a78066ee..aace57fae7f8 100644
--- a/drivers/soundwire/slave.c
+++ b/drivers/soundwire/slave.c
@@ -47,6 +47,7 @@ static int sdw_slave_add(struct sdw_bus *bus,
slave->bus = bus;
slave->status = SDW_SLAVE_UNATTACHED;
init_completion(&slave->enumeration_complete);
+ init_completion(&slave->initialization_complete);
slave->dev_num = 0;
init_completion(&slave->probe_complete);
slave->probed = false;