ALSA: control: Rename CONFIG_SND_CTL_VALIDATION to CONFIG_SND_CTL_DEBUG

The purpose of CONFIG_SND_CTL_VALIDATION is rather to enable the
debugging feature for the control API.  The validation is only a part
of it.  Let's rename it to be more explicit and intuitive.

While we're at it, let's advertise, give more comment to recommend
this feature for development in the kconfig help text.

Link: https://lore.kernel.org/r/20220609120219.3937-3-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>

include/sound/control.h

@@ -23,7 +23,7 @@ typedef int (snd_kcontrol_tlv_rw_t)(struct snd_kcontrol *kcontrol,
 				    unsigned int __user *tlv);
 
 /* internal flag for skipping validations */
-#ifdef CONFIG_SND_CTL_VALIDATION
+#ifdef CONFIG_SND_CTL_DEBUG
 #define SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK	(1 << 24)
 #define snd_ctl_skip_validation(info) \
 	((info)->access & SNDRV_CTL_ELEM_ACCESS_SKIP_CHECK)

sound/core/Kconfig

@@ -188,14 +188,19 @@ config SND_PCM_XRUN_DEBUG
 	  sound clicking when system is loaded, it may help to determine
 	  the process or driver which causes the scheduling gaps.
 
-config SND_CTL_VALIDATION
-	bool "Perform sanity-checks for each control element access"
+config SND_CTL_DEBUG
+	bool "Enable debugging feature for control API"
 	depends on SND_DEBUG
 	help
-	  Say Y to enable the additional validation of each control element
-	  access, including sanity-checks like whether the values returned
-	  from the driver are in the proper ranges or the check of the invalid
-	  access at out-of-array areas.
+	  Say Y to enable the debugging feature for ALSA control API.
+	  It performs the additional sanity-checks for each control element
+	  read access, such as whether the values returned from the driver
+	  are in the proper ranges or the check of the invalid access at
+	  out-of-array areas.  The error is printed when the driver gives
+	  such unexpected values.
+	  When you develop a driver that deals with control elements, it's
+	  strongly recommended to try this one once and verify whether you see
+	  any relevant errors or not.
 
 config SND_JACK_INJECTION_DEBUG
 	bool "Sound jack injection interface via debugfs"

sound/core/control.c

@@ -966,7 +966,7 @@ static const unsigned int value_sizes[] = {
 	[SNDRV_CTL_ELEM_TYPE_INTEGER64] = sizeof(long long),
 };
 
-#ifdef CONFIG_SND_CTL_VALIDATION
+#ifdef CONFIG_SND_CTL_DEBUG
 /* fill the remaining snd_ctl_elem_value data with the given pattern */
 static void fill_remaining_elem_value(struct snd_ctl_elem_value *control,
 				      struct snd_ctl_elem_info *info,
@@ -1188,7 +1188,7 @@ static int snd_ctl_elem_read(struct snd_card *card,
 
 	snd_ctl_build_ioff(&control->id, kctl, index_offset);
 
-#ifdef CONFIG_SND_CTL_VALIDATION
+#ifdef CONFIG_SND_CTL_DEBUG
 	/* info is needed only for validation */
 	memset(&info, 0, sizeof(info));
 	info.id = control->id;