[PATCH] ASoC: soc-component: improve error reporting for register access

[Srinivas Kandagatla]

Currently errors on register read/write/update are reported with
an error code and the corresponding function but does not provide
any details on the which register number did it actually fail.

register number can give better clue and it should be easy to
locate the code and fix.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla at linaro.org>
---

Personally I found this patch very useful while developing and debugging.

Ex: below error 
"ASoC: error at soc_component_read_no_lock on soc at 0:codec: -16"
did not provide much info except that it failed to read,
but after this patch error message looks like:
"ASoC: error at soc_component_read_no_lock on soc at 0:codec for register: [0x00003125] -16"
which was easy to locate and fix.

 sound/soc/soc-component.c | 26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/sound/soc/soc-component.c b/sound/soc/soc-component.c
index a08a897c5230..c76ff9c59dfb 100644
--- a/sound/soc/soc-component.c
+++ b/sound/soc/soc-component.c
@@ -13,9 +13,10 @@
 #include <sound/soc.h>
 #include <linux/bitops.h>
 
-#define soc_component_ret(dai, ret) _soc_component_ret(dai, __func__, ret)
+#define soc_component_ret(dai, ret) _soc_component_ret(dai, __func__, ret, -1)
+#define soc_component_ret_reg_rw(dai, ret, reg) _soc_component_ret(dai, __func__, ret, reg)
 static inline int _soc_component_ret(struct snd_soc_component *component,
-				     const char *func, int ret)
+				     const char *func, int ret, int reg)
 {
 	/* Positive/Zero values are not errors */
 	if (ret >= 0)
@@ -27,9 +28,14 @@ static inline int _soc_component_ret(struct snd_soc_component *component,
 	case -ENOTSUPP:
 		break;
 	default:
-		dev_err(component->dev,
-			"ASoC: error at %s on %s: %d\n",
-			func, component->name, ret);
+		if (reg == -1)
+			dev_err(component->dev,
+				"ASoC: error at %s on %s: %d\n",
+				func, component->name, ret);
+		else
+			dev_err(component->dev,
+				"ASoC: error at %s on %s for register: [0x%08x] %d\n",
+				func, component->name, reg, ret);
 	}
 
 	return ret;
@@ -687,7 +693,7 @@ static unsigned int soc_component_read_no_lock(
 		ret = -EIO;
 
 	if (ret < 0)
-		return soc_component_ret(component, ret);
+		return soc_component_ret_reg_rw(component, ret, reg);
 
 	return val;
 }
@@ -723,7 +729,7 @@ static int soc_component_write_no_lock(
 	else if (component->driver->write)
 		ret = component->driver->write(component, reg, val);
 
-	return soc_component_ret(component, ret);
+	return soc_component_ret_reg_rw(component, ret, reg);
 }
 
 /**
@@ -765,7 +771,7 @@ static int snd_soc_component_update_bits_legacy(
 
 	mutex_unlock(&component->io_mutex);
 
-	return soc_component_ret(component, ret);
+	return soc_component_ret_reg_rw(component, ret, reg);
 }
 
 /**
@@ -793,7 +799,7 @@ int snd_soc_component_update_bits(struct snd_soc_component *component,
 							   mask, val, &change);
 
 	if (ret < 0)
-		return soc_component_ret(component, ret);
+		return soc_component_ret_reg_rw(component, ret, reg);
 	return change;
 }
 EXPORT_SYMBOL_GPL(snd_soc_component_update_bits);
@@ -829,7 +835,7 @@ int snd_soc_component_update_bits_async(struct snd_soc_component *component,
 							   mask, val, &change);
 
 	if (ret < 0)
-		return soc_component_ret(component, ret);
+		return soc_component_ret_reg_rw(component, ret, reg);
 	return change;
 }
 EXPORT_SYMBOL_GPL(snd_soc_component_update_bits_async);
-- 
2.21.0