Commit a644a947 authored by Clemens Ladisch's avatar Clemens Ladisch
Browse files

ALSA: dice: optimize reading of consecutive registers 



Instead of reading two consecutive register with two quadlet requests,
use one block read request.

Signed-off-by: default avatarClemens Ladisch <clemens@ladisch.de>
parent a7304e3b

sound/firewire/dice.c

+11 −16
Original line number Diff line number Diff line
@@ -374,8 +374,8 @@ static int dice_open(struct snd_pcm_substream *substream) 
	};

	struct dice *dice = substream->private_data;

	struct snd_pcm_runtime *runtime = substream->runtime;

	__be32 clock_sel, number_audio, number_midi;

	unsigned int rate_index, rate;

	__be32 clock_sel, data[2];

	unsigned int rate_index, number_audio, number_midi;

	int err;



	err = dice_try_lock(dice);
@@ -393,30 +393,25 @@ static int dice_open(struct snd_pcm_substream *substream) 
		err = -ENXIO;

		goto err_lock;

	}

	rate = dice_rates[rate_index];



	err = snd_fw_transaction(dice->unit, TCODE_READ_QUADLET_REQUEST,

	err = snd_fw_transaction(dice->unit, TCODE_READ_BLOCK_REQUEST,

				 rx_address(dice, RX_NUMBER_AUDIO),

				 &number_audio, 4);

	if (err < 0)

		goto err_lock;

	err = snd_fw_transaction(dice->unit, TCODE_READ_QUADLET_REQUEST,

				 rx_address(dice, RX_NUMBER_MIDI),

				 &number_midi, 4);

				 data, 2 * 4);

	if (err < 0)

		goto err_lock;

	number_audio = be32_to_cpu(data[0]);

	number_midi = be32_to_cpu(data[1]);



	runtime->hw = hardware;



	runtime->hw.rates = snd_pcm_rate_to_rate_bit(rate);

	runtime->hw.rates = snd_pcm_rate_to_rate_bit(dice_rates[rate_index]);

	snd_pcm_limit_hw_rates(runtime);



	runtime->hw.channels_min = be32_to_cpu(number_audio);

	runtime->hw.channels_max = be32_to_cpu(number_audio);

	runtime->hw.channels_min = number_audio;

	runtime->hw.channels_max = number_audio;



	amdtp_out_stream_set_parameters(&dice->stream, rate,

					be32_to_cpu(number_audio),

					be32_to_cpu(number_midi));

	amdtp_out_stream_set_parameters(&dice->stream, dice_rates[rate_index],

					number_audio, number_midi);



	err = snd_pcm_hw_constraint_step(runtime, 0,

					 SNDRV_PCM_HW_PARAM_PERIOD_SIZE,