[2/5] ASoC: Intel: bdw-rt5677: fix module load/unload issues

Message ID 20200622154241.29053-3-pierre-louis.bossart@linux.intel.com
State Accepted
Commit bcb43fdae1c0d08b772b792cf46f323ad0d17968
Headers show
Series
  • Untitled series #28594
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Commit Message

Pierre-Louis Bossart June 22, 2020, 3:42 p.m.
The mainline code currently prevents modules from being removed.

The BE dailink .init() function calls devm_gpiod_get() using the codec
component device as argument. When the machine driver is removed, the
references to the gpiod are not released, and it's not possible to
remove the codec driver module - which is the only entity which could
free the gpiod.

This conceptual deadlock can be avoided by invoking gpiod_get() in the
.init() callback, and calling gpiod_put() in the exit() callback.

Tested on SAMUS Chromebook with SOF driver.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Reviewed-by: Curtis Malainey <curtis@malainey.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
---
 sound/soc/intel/boards/bdw-rt5677.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

Patch

diff --git a/sound/soc/intel/boards/bdw-rt5677.c b/sound/soc/intel/boards/bdw-rt5677.c
index 34a3abb5991f..c9da91147770 100644
--- a/sound/soc/intel/boards/bdw-rt5677.c
+++ b/sound/soc/intel/boards/bdw-rt5677.c
@@ -272,8 +272,8 @@  static int bdw_rt5677_init(struct snd_soc_pcm_runtime *rtd)
 			RT5677_CLK_SEL_SYS2);
 
 	/* Request rt5677 GPIO for headphone amp control */
-	bdw_rt5677->gpio_hp_en = devm_gpiod_get(component->dev, "headphone-enable",
-						GPIOD_OUT_LOW);
+	bdw_rt5677->gpio_hp_en = gpiod_get(component->dev, "headphone-enable",
+					   GPIOD_OUT_LOW);
 	if (IS_ERR(bdw_rt5677->gpio_hp_en)) {
 		dev_err(component->dev, "Can't find HP_AMP_SHDN_L gpio\n");
 		return PTR_ERR(bdw_rt5677->gpio_hp_en);
@@ -307,6 +307,19 @@  static int bdw_rt5677_init(struct snd_soc_pcm_runtime *rtd)
 	return 0;
 }
 
+static void bdw_rt5677_exit(struct snd_soc_pcm_runtime *rtd)
+{
+	struct bdw_rt5677_priv *bdw_rt5677 =
+			snd_soc_card_get_drvdata(rtd->card);
+
+	/*
+	 * The .exit() can be reached without going through the .init()
+	 * so explicitly test if the gpiod is valid
+	 */
+	if (!IS_ERR_OR_NULL(bdw_rt5677->gpio_hp_en))
+		gpiod_put(bdw_rt5677->gpio_hp_en);
+}
+
 /* broadwell digital audio interface glue - connects codec <--> CPU */
 SND_SOC_DAILINK_DEF(dummy,
 	DAILINK_COMP_ARRAY(COMP_DUMMY()));
@@ -372,6 +385,7 @@  static struct snd_soc_dai_link bdw_rt5677_dais[] = {
 		.dpcm_playback = 1,
 		.dpcm_capture = 1,
 		.init = bdw_rt5677_init,
+		.exit = bdw_rt5677_exit,
 #if !IS_ENABLED(CONFIG_SND_SOC_SOF_BROADWELL)
 		SND_SOC_DAILINK_REG(dummy, be, dummy),
 #else