3 files changed, 58 insertions, 9 deletions

diff --git a/sound/firewire/dice/dice-pcm.c b/sound/firewire/dice/dice-pcm.c
index 05e2e18b4c30..4aa0249826fd 100644
--- a/sound/firewire/dice/dice-pcm.c
+++ b/sound/firewire/dice/dice-pcm.c
@@ -332,16 +332,22 @@ int snd_dice_create_pcm(struct snd_dice *dice)
 	int err;
 
 	/* Check whether PCM substreams are required. */
-	max_capture = max_playback = 0;
-	err = snd_dice_transaction_read_tx(dice, TX_NUMBER, &reg, sizeof(reg));
-	if (err < 0)
-		return err;
-	max_capture = min_t(unsigned int, be32_to_cpu(reg), MAX_STREAMS);
+	if (dice->force_two_pcms) {
+		max_capture = max_playback = 2;
+	} else {
+		max_capture = max_playback = 0;
+		err = snd_dice_transaction_read_tx(dice, TX_NUMBER, &reg,
+						   sizeof(reg));
+		if (err < 0)
+			return err;
+		max_capture = min_t(unsigned int, be32_to_cpu(reg), MAX_STREAMS);
 
-	err = snd_dice_transaction_read_rx(dice, RX_NUMBER, &reg, sizeof(reg));
-	if (err < 0)
-		return err;
-	max_playback = min_t(unsigned int, be32_to_cpu(reg), MAX_STREAMS);
+		err = snd_dice_transaction_read_rx(dice, RX_NUMBER, &reg,
+						   sizeof(reg));
+		if (err < 0)
+			return err;
+		max_playback = min_t(unsigned int, be32_to_cpu(reg), MAX_STREAMS);
+	}
 
 	for (i = 0; i < MAX_STREAMS; i++) {
 		capture = playback = 0;
diff --git a/sound/firewire/dice/dice.c b/sound/firewire/dice/dice.c
index f7303a650ac2..8b64aef31a86 100644
--- a/sound/firewire/dice/dice.c
+++ b/sound/firewire/dice/dice.c
@@ -13,6 +13,8 @@ MODULE_LICENSE("GPL v2");
 
 #define OUI_WEISS		0x001c6a
 #define OUI_LOUD		0x000ff2
+#define OUI_FOCUSRITE		0x00130e
+#define OUI_TCELECTRONIC	0x001486
 
 #define DICE_CATEGORY_ID	0x04
 #define WEISS_CATEGORY_ID	0x00
@@ -20,6 +22,36 @@ MODULE_LICENSE("GPL v2");
 
 #define PROBE_DELAY_MS		(2 * MSEC_PER_SEC)
 
+/*
+ * Some models support several isochronous channels, while these streams are not
+ * always available. In this case, add the model name to this list.
+ */
+static bool force_two_pcm_support(struct fw_unit *unit)
+{
+	const char *const models[] = {
+		/* TC Electronic models. */
+		"StudioKonnekt48",
+		/* Focusrite models. */
+		"SAFFIRE_PRO_40",
+		"LIQUID_SAFFIRE_56",
+		"SAFFIRE_PRO_40_1",
+	};
+	char model[32];
+	unsigned int i;
+	int err;
+
+	err = fw_csr_string(unit->directory, CSR_MODEL, model, sizeof(model));
+	if (err < 0)
+		return false;
+
+	for (i = 0; i < ARRAY_SIZE(models); i++) {
+		if (strcmp(models[i], model) == 0)
+			break;
+	}
+
+	return i < ARRAY_SIZE(models);
+}
+
 static int check_dice_category(struct fw_unit *unit)
 {
 	struct fw_device *device = fw_parent_device(unit);
@@ -44,6 +76,12 @@ static int check_dice_category(struct fw_unit *unit)
 			break;
 		}
 	}
+
+	if (vendor == OUI_FOCUSRITE || vendor == OUI_TCELECTRONIC) {
+		if (force_two_pcm_support(unit))
+			return 0;
+	}
+
 	if (vendor == OUI_WEISS)
 		category = WEISS_CATEGORY_ID;
 	else if (vendor == OUI_LOUD)
@@ -150,6 +188,9 @@ static void do_registration(struct work_struct *work)
 	if (err < 0)
 		return;
 
+	if (force_two_pcm_support(dice->unit))
+		dice->force_two_pcms = true;
+
 	err = snd_dice_transaction_init(dice);
 	if (err < 0)
 		goto error;
diff --git a/sound/firewire/dice/dice.h b/sound/firewire/dice/dice.h
index 8fba87d83810..e6c07857f475 100644
--- a/sound/firewire/dice/dice.h
+++ b/sound/firewire/dice/dice.h
@@ -97,6 +97,8 @@ struct snd_dice {
 	bool global_enabled;
 	struct completion clock_accepted;
 	unsigned int substreams_counter;
+
+	bool force_two_pcms;
 };
 
 enum snd_dice_addr_type {