ALSA: dice: restrict the driver to playback-only devices
At the moment, this driver supports only playback, while FFADO supports
(only) full-duplex devices. So, prevent conflicts by not claiming
devices that would be better handled by FFADO.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
diff --git a/sound/firewire/dice.c b/sound/firewire/dice.c
index 49d630b..6feee66 100644
--- a/sound/firewire/dice.c
+++ b/sound/firewire/dice.c
@@ -1128,6 +1128,7 @@
int key, value, vendor = -1, model = -1, err;
unsigned int category, i;
__be32 pointers[ARRAY_SIZE(min_values)];
+ __be32 tx_data[4];
__be32 version;
/*
@@ -1171,6 +1172,14 @@
return -ENODEV;
}
+ /* We support playback only. Let capture devices be handled by FFADO. */
+ err = snd_fw_transaction(unit, TCODE_READ_BLOCK_REQUEST,
+ DICE_PRIVATE_SPACE +
+ be32_to_cpu(pointers[2]) * 4,
+ tx_data, sizeof(tx_data), 0);
+ if (err < 0 || (tx_data[0] && tx_data[3]))
+ return -ENODEV;
+
/*
* Check that the implemented DICE driver specification major version
* number matches.