Re: [alsa-devel] [PATCH 2/3] fireface: add transaction support

On Dec 08 2015 19:22, Clemens Ladisch wrote:

Takashi Sakamoto wrote:

...

+static void transmit_midi_msg(struct snd_ff *ff, unsigned int port) ...

• /* Retrieve one MIDI byte to calculate length of the message. */
• len = snd_rawmidi_transmit_peek(substream, buf,

• 			SND_FF_MAXIMIM_MIDI_QUADS);
  

SND_FF_MAXIMIM_MIDI_QUADS does not have the value 1.

Oops. It's my mistake to left the message as what it had been. Originally, I programmed to retrieve one byte. Later, I investigated the maximum message size and changed the code.

...

• /* Calculate consume bytes. */
  

• consume = calculate_message_bytes(status);
  

• if (consume <= 0)
  

• 	return;
  

As far as I can see, sending one of the "undefined" bytes can stop the stream permanently. Invalid bytes need to be acked to ignore/remove them.

Exactly. We should find better way to handle such messages. Do you have any good ideas?

Thanks

Takashi Sakamoto