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>
This commit is contained in:
Clemens Ladisch 2013-10-15 20:26:05 +02:00
parent a471fcde8c
commit b20be8de1b
2 changed files with 15 additions and 4 deletions

View File

@ -12,14 +12,16 @@ config SND_FIREWIRE_LIB
depends on SND_PCM
config SND_DICE
tristate "DICE devices (EXPERIMENTAL)"
tristate "DICE-based DACs (EXPERIMENTAL)"
select SND_HWDEP
select SND_PCM
select SND_FIREWIRE_LIB
help
Say Y here to include support for many FireWire audio interfaces
based on the DICE chip family (DICE-II/Jr/Mini) from TC Applied
Technologies.
Say Y here to include support for many DACs based on the DICE
chip family (DICE-II/Jr/Mini) from TC Applied Technologies.
At the moment, this driver supports playback only. If you
want to use devices that support capturing, use FFADO instead.
To compile this driver as a module, choose M here: the module
will be called snd-dice.

View File

@ -1128,6 +1128,7 @@ static int dice_interface_check(struct fw_unit *unit)
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 @@ static int dice_interface_check(struct fw_unit *unit)
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.