ASoC: meson: add helpers for clk_disable_unprepare

From: Arnd Bergmann <[email protected]>

Casting between incompatible function types causes a warning with clang-16 because it breaks control flow integrity (KCFI) rules:

sound/soc/meson/aiu.c:243:12: error: cast from 'void (*)(struct clk *)' to 'void (*)(void *)' converts to incompatible function type [-Werror,-Wcast-function-type-strict]

   243 |                                        (void(*)(void *))clk_disable_unprepare,
       |                                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

include/linux/device.h:406:34: note: expanded from macro 'devm_add_action_or_reset'
406 | __devm_add_action_or_reset(dev, action, data, #action)
| ^~~~~~
sound/soc/meson/t9015.c:274:4: error: cast from 'void (*)(struct clk *)' to 'void (*)(void *)' converts to incompatible function type [-Werror,-Wcast-function-type-strict]

   274 |                         (void(*)(void *))clk_disable_unprepare,
       |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

include/linux/device.h:406:34: note: expanded from macro 'devm_add_action_or_reset'
406 | __devm_add_action_or_reset(dev, action, data, #action)
| ^~~~~~

These two meson drivers cast clk_disable_unprepare() into a different type in order to have it automatically called from the driver relase. Add trivial helpers to do the same using correct types.

Fixes 33901f5b9b16 ("ASoC: meson: add t9015 internal DAC driver")

Fixes 6ae9ca9ce986 ("ASoC: meson: aiu: add i2s and spdif support")

Signed-off-by Arnd Bergmann <[email protected]>

---
  sound/soc/meson/aiu.c   | 9 ++++++---
  sound/soc/meson/t9015.c | 9 ++++++---
  2 files changed, 12 insertions(+), 6 deletions(-)

sound/soc/meson/aiu.c +6 -3

index 7109b81cc3d0..211f360df284 100644
@@ -209,6 +209,11 @@ static const char * const aiu_spdif_ids[] = {
  	[MCLK]	= "spdif_mclk_sel"
  };
 
+static void aiu_clk_disable(void *clk)
+{
+	clk_disable_unprepare(clk);
+}
+
  static int aiu_clk_get(struct device *dev)
  {
  	struct aiu *aiu = dev_get_drvdata(dev);

@@ -239,9 +244,7 @@ static int aiu_clk_get(struct device *dev)
  		return ret;
  	}
 
-	ret = devm_add_action_or_reset(dev,
-				       (void(*)(void *))clk_disable_unprepare,
-				       aiu->pclk);
+	ret = devm_add_action_or_reset(dev, aiu_clk_disable, aiu->pclk);
  	if (ret)
  		dev_err(dev, "failed to add reset action on pclk");
 

sound/soc/meson/t9015.c +5 -0

index 9c6b4dac6893..e0f9a603a5e9 100644
@@ -243,6 +243,11 @@ static const struct regmap_config t9015_regmap_config = {
  	.max_register		= POWER_CFG,
  };
 
+static void t9015_clk_disable(void *clk)
+{
+	clk_disable_unprepare(clk);
+}
+
  static int t9015_probe(struct platform_device *pdev)
  {
  	struct device *dev = &pdev->dev;

From: Arnd Bergmann <[email protected]>

Casting between incompatible function types causes a warning with clang-16 because it breaks control flow integrity (KCFI) rules:

sound/soc/meson/aiu.c:243:12: error: cast from 'void (*)(struct clk *)' to 'void (*)(void *)' converts to incompatible function type [-Werror,-Wcast-function-type-strict]

  243 |                                        (void(*)(void *))clk_disable_unprepare,
      |                                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

include/linux/device.h:406:34: note: expanded from macro 'devm_add_action_or_reset'
406 | __devm_add_action_or_reset(dev, action, data, #action)
| ^~~~~~
sound/soc/meson/t9015.c:274:4: error: cast from 'void (*)(struct clk *)' to 'void (*)(void *)' converts to incompatible function type [-Werror,-Wcast-function-type-strict]

  274 |                         (void(*)(void *))clk_disable_unprepare,
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

include/linux/device.h:406:34: note: expanded from macro 'devm_add_action_or_reset'
406 | __devm_add_action_or_reset(dev, action, data, #action)
| ^~~~~~

These two meson drivers cast clk_disable_unprepare() into a different type in order to have it automatically called from the driver relase. Add trivial helpers to do the same using correct types.

Fixes 33901f5b9b16 ("ASoC: meson: add t9015 internal DAC driver")

Fixes 6ae9ca9ce986 ("ASoC: meson: aiu: add i2s and spdif support")

Signed-off-by Arnd Bergmann <[email protected]>

---
 sound/soc/meson/aiu.c   | 9 ++++++---
 sound/soc/meson/t9015.c | 9 ++++++---
 2 files changed, 12 insertions(+), 6 deletions(-)

sound/soc/meson/aiu.c +5 -0

index 7109b81cc3d0..211f360df284 100644
@@ -209,6 +209,11 @@ static const char * const aiu_spdif_ids[] = {
 	[MCLK]	= "spdif_mclk_sel"
 };
 
+static void aiu_clk_disable(void *clk)
+{
+	clk_disable_unprepare(clk);
+}
+
 static int aiu_clk_get(struct device *dev)
 {
 	struct aiu *aiu = dev_get_drvdata(dev);

sound/soc/meson/aiu.c +0 -0

 	if (ret)
 		dev_err(dev, "failed to add reset action on pclk");
 

sound/soc/meson/t9015.c +6 -3

index 9c6b4dac6893..e0f9a603a5e9 100644
@@ -243,6 +243,11 @@ static const struct regmap_config t9015_regmap_config = {
 	.max_register		= POWER_CFG,
 };
 
+static void t9015_clk_disable(void *clk)
+{
+	clk_disable_unprepare(clk);
+}
+
 static int t9015_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;

@@ -270,9 +275,7 @@ static int t9015_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	ret = devm_add_action_or_reset(dev,
-			(void(*)(void *))clk_disable_unprepare,
-			priv->pclk);
+	ret = devm_add_action_or_reset(dev, t9015_clk_disable, priv->pclk);
 	if (ret)
 		return ret;

On Tue 13 Feb 2024 at 11:11, Arnd Bergmann <[email protected]> wrote:

This probably pre-dates the introduction of devm_clk_get_enabled() It would probably be better to use that instead of duplicating helper functions which do the same thing.

If for any reason it is not possible, a common helper in clk.h would preferable I think.

Quoted 5 lines · Jerome Brunet

On Tue 13 Feb 2024 at 11:11, Arnd Bergmann <[email protected]> wrote:

This probably pre-dates the introduction of devm_clk_get_enabled() It would probably be better to use that instead of duplicating helper functions which do the same thing.

Ah, I had not thought of that interface either, so you are probably right that this is the best way to do it.
Can you send a replacement patch then and add my Reported-by?

I also sent the same patch for drivers/nvmem/meson-efuse.c, which I guess will also need the same treatment. I also checked and saw that all three files already had this code in linux-6.0 when devm_clk_get_enabled() got added.

Quoted 2 lines

If for any reason it is not possible, a common helper in clk.h would preferable I think.

I can't think of anything that prevents us from using devm_clk_get_enabled() here.

Arnd

Quoted 10 lines · Arnd Bergmann

Quoted 5 lines · Jerome Brunet

On Tue 13 Feb 2024 at 11:11, Arnd Bergmann <[email protected]> wrote:

This probably pre-dates the introduction of devm_clk_get_enabled() It would probably be better to use that instead of duplicating helper functions which do the same thing.

Ah, I had not thought of that interface either, so you are probably right that this is the best way to do it.
Can you send a replacement patch then and add my Reported-by?

Sure.

How may I reproduce the problem ?
Just tried with 'Debian clang version 16.0.6 (19)', no warning.

I suppose I need to add something ?