ASoC: improve the DMI long card code in asoc-core

Add append_dmi_string() function and make the code more readable.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20191120174435.30920-1-perex@perex.cz
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/soc-core.c

@@ -1718,6 +1718,23 @@ static int is_dmi_valid(const char *field)
 	return 1;
 }
 
+/*
+ * Append a string to card->dmi_longname with character cleanups.
+ */
+static void append_dmi_string(struct snd_soc_card *card, const char *str)
+{
+	char *dst = card->dmi_longname;
+	size_t dst_len = sizeof(card->dmi_longname);
+	size_t len;
+
+	len = strlen(dst);
+	snprintf(dst + len, dst_len - len, "-%s", str);
+
+	len++;	/* skip the separator "-" */
+	if (len < dst_len)
+		cleanup_dmi_name(dst + len);
+}
+
 /**
  * snd_soc_set_dmi_name() - Register DMI names to card
  * @card: The card to register DMI names
@@ -1752,61 +1769,36 @@ static int is_dmi_valid(const char *field)
 int snd_soc_set_dmi_name(struct snd_soc_card *card, const char *flavour)
 {
 	const char *vendor, *product, *product_version, *board;
-	size_t longname_buf_size = sizeof(card->snd_card->longname);
-	size_t len;
 
 	if (card->long_name)
 		return 0; /* long name already set by driver or from DMI */
 
-	/* make up dmi long name as: vendor.product.version.board */
+	/* make up dmi long name as: vendor-product-version-board */
 	vendor = dmi_get_system_info(DMI_BOARD_VENDOR);
 	if (!vendor || !is_dmi_valid(vendor)) {
 		dev_warn(card->dev, "ASoC: no DMI vendor name!\n");
 		return 0;
 	}
 
-	snprintf(card->dmi_longname, sizeof(card->snd_card->longname),
-			 "%s", vendor);
+	snprintf(card->dmi_longname, sizeof(card->dmi_longname), "%s", vendor);
 	cleanup_dmi_name(card->dmi_longname);
 
 	product = dmi_get_system_info(DMI_PRODUCT_NAME);
 	if (product && is_dmi_valid(product)) {
-		len = strlen(card->dmi_longname);
-		snprintf(card->dmi_longname + len,
-			 longname_buf_size - len,
-			 "-%s", product);
-
-		len++;	/* skip the separator "-" */
-		if (len < longname_buf_size)
-			cleanup_dmi_name(card->dmi_longname + len);
+		append_dmi_string(card, product);
 
 		/*
 		 * some vendors like Lenovo may only put a self-explanatory
 		 * name in the product version field
 		 */
 		product_version = dmi_get_system_info(DMI_PRODUCT_VERSION);
-		if (product_version && is_dmi_valid(product_version)) {
-			len = strlen(card->dmi_longname);
-			snprintf(card->dmi_longname + len,
-				 longname_buf_size - len,
-				 "-%s", product_version);
-
-			len++;
-			if (len < longname_buf_size)
-				cleanup_dmi_name(card->dmi_longname + len);
-		}
+		if (product_version && is_dmi_valid(product_version))
+			append_dmi_string(card, product_version);
 	}
 
 	board = dmi_get_system_info(DMI_BOARD_NAME);
 	if (board && is_dmi_valid(board)) {
-		len = strlen(card->dmi_longname);
-		snprintf(card->dmi_longname + len,
-			 longname_buf_size - len,
-			 "-%s", board);
-
-		len++;
-		if (len < longname_buf_size)
-			cleanup_dmi_name(card->dmi_longname + len);
+		append_dmi_string(card, board);
 	} else if (!product) {
 		/* fall back to using legacy name */
 		dev_warn(card->dev, "ASoC: no DMI board/product name!\n");
@@ -1814,16 +1806,8 @@ int snd_soc_set_dmi_name(struct snd_soc_card *card, const char *flavour)
 	}
 
 	/* Add flavour to dmi long name */
-	if (flavour) {
-		len = strlen(card->dmi_longname);
-		snprintf(card->dmi_longname + len,
-			 longname_buf_size - len,
-			 "-%s", flavour);
-
-		len++;
-		if (len < longname_buf_size)
-			cleanup_dmi_name(card->dmi_longname + len);
-	}
+	if (flavour)
+		append_dmi_string(card, flavour);
 
 	/* set the card long name */
 	card->long_name = card->dmi_longname;