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Fix various audio DMA issues:

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RP2040 and SAMD51:
- Detect when DMA has finished, and stop DMA audio explicitly.
- Do not accidentally reuse `first_buffer` supplied by WaveFile or RawSample. Always realloc `first_buffer` and `second_buffer`

RP2040:
- When audio playing is stopped, write a final zero to the output register. This prevents residual PWM tones.
- Handle buffer size for 8-bit samples properly for 16-bit output.
- Fail on some edge cases (which may not be possible at the moment).
This commit is contained in:
Dan Halbert 2021-07-30 13:54:33 -04:00
parent 2cd80d1074
commit 59b89fdc5c
4 changed files with 32 additions and 18 deletions
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8
ports/atmel-samd/audio_dma.c
View File

@ -157,7 +157,13 @@ void audio_dma_load_next_block(audio_dma_t *dma) {
if (dma->loop) {
audiosample_reset_buffer(dma->sample, dma->single_channel_output, dma->audio_channel);
} else {
descriptor->DESCADDR.reg = 0;
if ((output_buffer_length == 0) && dma_transfer_status(SHARED_RX_CHANNEL) & 0x3) {
// Nothing further to read and previous buffer is finished.
audio_dma_stop(dma);
} else {
// Break descriptor chain.
descriptor->DESCADDR.reg = 0;
}
}
}
descriptor->BTCTRL.bit.VALID = true;

4
ports/atmel-samd/common-hal/audiobusio/I2SOut.c
View File

@ -44,7 +44,7 @@
#include "atmel_start_pins.h"
#include "hal/include/hal_gpio.h"
#include "hpl/gclk/hpl_gclk_base.h"
#include "hpl//hpl_gclk_base.h"
#include "peripheral_clk_config.h"
#ifdef SAMD21
@ -379,7 +379,7 @@ void common_hal_audiobusio_i2sout_stop(audiobusio_i2sout_obj_t *self) {
}
#endif
disconnect_gclk_from_peripheral(self->gclk, I2S_GCLK_ID_0 + self->clock_unit);
disable_gclk(self->gclk);
disable_clock_generator(self->gclk);
#ifdef SAM_D5X_E5X
connect_gclk_to_peripheral(5, I2S_GCLK_ID_0 + self->clock_unit);

37
ports/raspberrypi/audio_dma.c
View File

@ -150,15 +150,7 @@ void audio_dma_load_next_block(audio_dma_t *dma) {
audio_dma_stop(dma);
return;
}
bool busy0 = dma_channel_is_busy(dma->channel[0]);
bool busy1 = dma_channel_is_busy(dma->channel[1]);
if (busy0 == busy1) {
mp_printf(&mp_plat_print, "busy: %d %d\n", busy0, busy1);
}
if (buffer_length < 256) {
mp_printf(&mp_plat_print, "%d length: %d\n", dma->first_channel_free, buffer_length);
}
audio_dma_convert_signed(dma, buffer, buffer_length, &output_buffer, &output_buffer_length);
// If we don't have an output buffer, save the pointer to first_buffer for use in the single
@ -169,13 +161,21 @@ void audio_dma_load_next_block(audio_dma_t *dma) {
dma_channel_set_trans_count(dma_channel, output_buffer_length / dma->output_size, false /* trigger */);
dma_channel_set_read_addr(dma_channel, output_buffer, false /* trigger */);
if (get_buffer_result == GET_BUFFER_DONE) {
if (dma->loop) {
audiosample_reset_buffer(dma->sample, dma->single_channel_output, dma->audio_channel);
} else {
// Set channel trigger to ourselves so we don't keep going.
dma_channel_hw_t *c = &dma_hw->ch[dma_channel];
c->al1_ctrl = (c->al1_ctrl & ~DMA_CH0_CTRL_TRIG_CHAIN_TO_BITS) | (dma_channel << DMA_CH0_CTRL_TRIG_CHAIN_TO_LSB);
if (output_buffer_length == 0 &&
!dma_channel_is_busy(dma->channel[0]) &&
!dma_channel_is_busy(dma->channel[1])) {
// No data has been read, and both DMA channels have now finished, so it's safe to stop.
audio_dma_stop(dma);
} else {
// Set channel trigger to ourselves so we don't keep going.
dma_channel_hw_t *c = &dma_hw->ch[dma_channel];
c->al1_ctrl = (c->al1_ctrl & ~DMA_CH0_CTRL_TRIG_CHAIN_TO_BITS) | (dma_channel << DMA_CH0_CTRL_TRIG_CHAIN_TO_LSB);
}
}
}
}
@ -217,6 +217,8 @@ audio_dma_result audio_dma_setup_playback(audio_dma_t *dma,
dma->first_channel_free = true;
dma->output_resolution = output_resolution;
dma->sample_resolution = audiosample_bits_per_sample(sample);
dma->output_register_address = output_register_address;
audiosample_reset_buffer(sample, single_channel_output, audio_channel);
bool single_buffer;
@ -224,11 +226,8 @@ audio_dma_result audio_dma_setup_playback(audio_dma_t *dma,
uint32_t max_buffer_length;
audiosample_get_buffer_structure(sample, single_channel_output, &single_buffer, &samples_signed,
&max_buffer_length, &dma->sample_spacing);
mp_printf(&mp_plat_print, "single_buffer: %d, samples_signed: %d, max_buffer_length: %d, dma->sample_spacing: %d\n",
single_buffer, samples_signed, max_buffer_length, dma->sample_spacing); ////
// Check to see if we have to scale the resolution up.
mp_printf(&mp_plat_print, "dma->sample_resolution: %d, dma->output_resolution: %d, output_signed: %d, single_channel_output: %d\n",
dma->sample_resolution, dma->output_resolution, output_signed, single_channel_output);
if (dma->sample_resolution <= 8 && dma->output_resolution > 8) {
max_buffer_length *= 2;
}
@ -343,6 +342,14 @@ void audio_dma_stop(audio_dma_t *dma) {
if (dma_channel_is_busy(channel)) {
dma_channel_abort(channel);
}
// Write a zero as the last sample. This stops any PWM output.
if (dma->output_resolution <= 8) {
*((uint8_t *)dma->output_register_address) = 0;
} else {
*((uint16_t *)dma->output_register_address) = 0;
}
dma_channel_set_read_addr(channel, NULL, false /* trigger */);
dma_channel_set_write_addr(channel, NULL, false /* trigger */);
dma_channel_set_trans_count(channel, 0, false /* trigger */);

1
ports/raspberrypi/audio_dma.h
View File

@ -51,6 +51,7 @@ typedef struct {
size_t first_buffer_length;
uint8_t *second_buffer;
size_t second_buffer_length;
uint32_t output_register_address;
background_callback_t callback;
} audio_dma_t;