ASoC: Drop invalid DMI fields when setting card long name from DMI info

Sometimes DMI fields may be invalid and so can't give useful vendor,
product or board info, such as "Type2 - Board Manufacturer" or
"Type1 - TBD by OEM". Including such invalid DMI fileds may create silly
card long name. So this patch creates a black list of invalid strings.
And if a DMI field contains any string in this list, it will be excluded
from the card long name.

Signed-off-by: Mengdong Lin <mengdong.lin@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/soc-core.c

@@ -68,6 +68,20 @@ static int pmdown_time = 5000;
 module_param(pmdown_time, int, 0);
 MODULE_PARM_DESC(pmdown_time, "DAPM stream powerdown time (msecs)");
 
+/* If a DMI filed contain strings in this blacklist (e.g.
+ * "Type2 - Board Manufacturer" or  "Type1 - TBD by OEM"), it will be taken
+ * as invalid and dropped when setting the card long name from DMI info.
+ */
+static const char * const dmi_blacklist[] = {
+	"To be filled by OEM",
+	"TBD by OEM",
+	"Default String",
+	"Board Manufacturer",
+	"Board Vendor Name",
+	"Board Product Name",
+	NULL,	/* terminator */
+};
+
 /* returns the minimum number of bytes needed to represent
  * a particular given value */
 static int min_bytes_needed(unsigned long val)
@@ -1933,6 +1947,22 @@ static void cleanup_dmi_name(char *name)
 	name[j] = '\0';
 }
 
+/* Check if a DMI field is valid, i.e. not containing any string
+ * in the black list.
+ */
+static int is_dmi_valid(const char *field)
+{
+	int i = 0;
+
+	while (dmi_blacklist[i]) {
+		if (strstr(field, dmi_blacklist[i]))
+			return 0;
+		i++;
+	};
+
+	return 1;
+}
+
 /**
  * snd_soc_set_dmi_name() - Register DMI names to card
  * @card: The card to register DMI names
@@ -1975,17 +2005,18 @@ int snd_soc_set_dmi_name(struct snd_soc_card *card, const char *flavour)
 
 	/* make up dmi long name as: vendor.product.version.board */
 	vendor = dmi_get_system_info(DMI_BOARD_VENDOR);
-	if (!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);
 	cleanup_dmi_name(card->dmi_longname);
 
 	product = dmi_get_system_info(DMI_PRODUCT_NAME);
-	if (product) {
+	if (product && is_dmi_valid(product)) {
 		len = strlen(card->dmi_longname);
 		snprintf(card->dmi_longname + len,
 			 longname_buf_size - len,
@@ -1999,7 +2030,7 @@ int snd_soc_set_dmi_name(struct snd_soc_card *card, const char *flavour)
 		 * name in the product version field
 		 */
 		product_version = dmi_get_system_info(DMI_PRODUCT_VERSION);
-		if (product_version) {
+		if (product_version && is_dmi_valid(product_version)) {
 			len = strlen(card->dmi_longname);
 			snprintf(card->dmi_longname + len,
 				 longname_buf_size - len,
@@ -2012,7 +2043,7 @@ int snd_soc_set_dmi_name(struct snd_soc_card *card, const char *flavour)
 	}
 
 	board = dmi_get_system_info(DMI_BOARD_NAME);
-	if (board) {
+	if (board && is_dmi_valid(board)) {
 		len = strlen(card->dmi_longname);
 		snprintf(card->dmi_longname + len,
 			 longname_buf_size - len,