[RFC PATCH 2/2] ASoC: SOF: trigger re-probing of deferred devices from workqueue

[Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>]

Audio drivers such as HDaudio legacy and SOF rely on a workqueue to
split the probe into two, with a first pass returning success
immediately, and the second pass taking a lot more time due to the use
of request_module() and the DSP initializations.

This workqueue-based solution helps deal with conflicting requirements
a) other drivers should not be blocked by a long probe
b) a PROBE_PREFER_ASYNCHRONOUS probe_type is explicitly not allowed
to avoid a deadlock when request_module() is used.

This patch makes sure the deferred probe framework is triggered when
the provider of resources successfully completes its initialization.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
---
 sound/soc/sof/core.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sound/soc/sof/core.c b/sound/soc/sof/core.c
index 3e4dd4a86363..cecc0e914807 100644
--- a/sound/soc/sof/core.c
+++ b/sound/soc/sof/core.c
@@ -251,6 +251,9 @@ static int sof_probe_continue(struct snd_sof_dev *sdev)
 
 	sdev->probe_completed = true;
 
+	/* kick-off re-probing of deferred devices */
+	driver_deferred_probe_trigger();
+
 	return 0;
 
 fw_trace_err:
-- 
2.25.1