linux-toradex.git/sound/firewire/lib.c, branch v4.4.33

ALSA: firewire-lib: avoid NULL pointer dereference after closing MIDI port

2015-10-19T09:58:21+00:00

When asynchronous MIDI port is closed before callbacked, the callback
function causes NULL pointer dereference to missing MIDI substream.

This commit fixes this bug.

Fixes: e8a40d9bcb23('ALSA: firewire-lib: schedule work again when MIDI substream has rest of MIDI messages')
Reported-by: Dan Carpenter 
Signed-off-by: Takashi Sakamoto 
Signed-off-by: Takashi Iwai

ALSA: firewire-lib: avoid endless loop to transfer MIDI messages at fatal error

2015-10-09T07:57:06+00:00

Currently, when asynchronous transactions finish in error state and
retries, work scheduling and work running also continues. This
should be canceled at fatal error because it can cause endless loop.

This commit enables to cancel transferring MIDI messages when transactions
encounter fatal errors. This is achieved by setting error state.

Signed-off-by: Takashi Sakamoto 
Signed-off-by: Takashi Iwai

ALSA: firewire-lib: add throttle for MIDI data rate

2015-10-09T07:57:06+00:00

Typically, the target devices have internal buffer to adjust output of
received MIDI messages for MIDI serial bus, while the capacity of the
buffer is limited. IEEE 1394 transactions can transfer more MIDI messages
than MIDI serial bus can. This can cause buffer over flow in device side.

This commit adds throttle to limit MIDI data rate by counting intervals
between two MIDI messages. Usual MIDI messages consists of two or three
bytes. This requires 1.302 to 1.953 mili-seconds interval between these
messages. This commit uses kernel monotonic time service to calculate the
time of next transaction.

Signed-off-by: Takashi Sakamoto 
Signed-off-by: Takashi Iwai

ALSA: firewire-lib: schedule work again when MIDI substream has rest of MIDI messages

2015-10-09T07:57:05+00:00

Currently, when two MIDI trigger callbacks can be called immediately,
transactions for the second MIDI messages can be postpone till next trigger
callback. This is not good for real-time message transmission.

This commit schedules work again at response handling callback if the
MIDI substream still includes untransferred MIDI messages.

Signed-off-by: Takashi Sakamoto 
Signed-off-by: Takashi Iwai

ALSA: firewire-lib: add a restriction for a transaction at once

2015-10-09T07:57:05+00:00

Currently, when waiting for a response, callers can start another
transaction by scheduling another work. This is not good for error
processing of transaction, especially the first response is too late.

This commit serialize request/response transactions, by adding one
boolean member to represent idling state.

Signed-off-by: Takashi Sakamoto 
Signed-off-by: Takashi Iwai

ALSA: firewire-lib: add helper functions for asynchronous transactions to transfer MIDI messages

2015-10-09T07:57:04+00:00

Some models receive MIDI messages via IEEE 1394 asynchronous transactions.
In this case, MIDI messages are transferred in fixed-length payload. It's
nice that firewire-lib module has common helper functions.

This commit implements this idea. Each driver adds
'struct snd_fw_async_midi_port' in its instance structure. In probing,
it should call snd_fw_async_midi_port_init() to initialize the
structure with some parameters such as target address, the length
of payload in a transaction and a pointer for callback function
to fill the payload buffer. At 'struct snd_rawmidi_ops.trigger()'
callback, it should call 'snd_fw_async_midi_port_run()' to start
transactions. Each driver should ensure that the lifetime of MIDI
substream continues till calling 'snd_fw_async_midi_port_finish()'.

The helper functions support retries to transferring MIDI messages when
transmission errors occur. When transactions are successful, the helper
functions call 'snd_rawmidi_transmit_ack()' internally to consume MIDI
bytes in the buffer. Therefore, Each driver is expected to use
'snd_rawmidi_transmit_peek()' to tell the number of bytes to transfer to
return value of 'fill' callback.

Signed-off-by: Takashi Sakamoto 
Signed-off-by: Takashi Iwai

ALSA: firewire: extend snd_fw_transaction()

2013-10-20T20:07:57+00:00

Add a flag to snd_fw_transaction() to allow it to abort when a bus reset
happens.  This removes most of the duplicated error handling loops that
were required around calls to the low-level fw_run_transaction().

Also add a flag to suppress error messages; errors are expected when we
attempt to clean up after the device was unplugged.

Signed-off-by: Clemens Ladisch

firewire: move rcode_string() to core

2012-04-17T20:54:55+00:00

There is nothing audio-specific about the rcode_string() helper, so move
it from snd-firewire-lib into firewire-core to allow other code to use it.

Signed-off-by: Clemens Ladisch 
Signed-off-by: Stefan Richter  (fixed sound/firewire/cmp.c)

ALSA: add LaCie FireWire Speakers/Griffin FireWave Surround driver

2011-03-15T07:42:22+00:00

Add a driver for two playback-only FireWire devices based on the OXFW970
chip.

v2: better AMDTP API abstraction; fix fw_unit leak; small fixes
v3: cache the iPCR value
v4: FireWave constraints; fix fw_device reference counting;
    fix PCR caching; small changes and fixes
v5: volume/mute support; fix crashing due to pcm stop races
v6: fix build; one-channel volume for LaCie
v7: use signed values to make volume (range checks) work; fix function
    block IDs for volume/mute; always use channel 0 for LaCie volume

Signed-off-by: Clemens Ladisch 
Acked-by: Stefan Richter 
Tested-by: Jay Fenlason 
Signed-off-by: Takashi Iwai