ASoC: core: conditionally increase module refcount on component open

Recently, for Intel platforms the "ignore_module_refcount" field
was introduced for the component driver. In order to avoid a
deadlock preventing the PCI modules from being removed
even when the card was idle, the refcounts were not incremented
for the device driver module during component probe.

However, this change introduced a nasty side effect:
the device driver module can be unloaded while a pcm stream is open.

This patch proposes to change the field to be renamed as
"module_get_upon_open". When this field is set, the module
refcount should be incremented on pcm open amd decremented
upon pcm close. This will enable modules to be removed
when no PCM playback/capture happens and prevent removal
when the component is actually in use.

Also, align with the skylake component driver with the new name.

Fixes: b450b878('ASoC: core: don't increase component module refcount
                 unconditionally'
Signed-off-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Acked-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

2 files changed, 3 insertions, 3 deletions

diff --git a/sound/soc/intel/skylake/skl-pcm.c b/sound/soc/intel/skylake/skl-pcm.c
index 57031b6d4d45..9735e2412251 100644
--- a/sound/soc/intel/skylake/skl-pcm.c
+++ b/sound/soc/intel/skylake/skl-pcm.c
@@ -1475,7 +1475,7 @@ static const struct snd_soc_component_driver skl_component  = {
 	.ops		= &skl_platform_ops,
 	.pcm_new	= skl_pcm_new,
 	.pcm_free	= skl_pcm_free,
-	.ignore_module_refcount = 1, /* do not increase the refcount in core */
+	.module_get_upon_open = 1, /* increment refcount when a pcm is opened */
 };
 
 int skl_platform_register(struct device *dev)
diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index d88757659729..46e3ab0fced4 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -947,7 +947,7 @@ static void soc_cleanup_component(struct snd_soc_component *component)
 	snd_soc_dapm_free(snd_soc_component_get_dapm(component));
 	soc_cleanup_component_debugfs(component);
 	component->card = NULL;
-	if (!component->driver->ignore_module_refcount)
+	if (!component->driver->module_get_upon_open)
 		module_put(component->dev->driver->owner);
 }
 
@@ -1381,7 +1381,7 @@ static int soc_probe_component(struct snd_soc_card *card,
 		return 0;
 	}
 
-	if (!component->driver->ignore_module_refcount &&
+	if (!component->driver->module_get_upon_open &&
 	    !try_module_get(component->dev->driver->owner))
 		return -ENODEV;