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Use only DMA0 for PIO background read/write #9980

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Merged
merged 2 commits into from
Jan 23, 2025
Merged

Use only DMA0 for PIO background read/write #9980

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f593813
Use only DMA0 for PIO background read/write
dhalbert Jan 19, 2025
a9d41bb
fix bugs noticed in review by @relic-se
dhalbert Jan 23, 2025
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26 changes: 6 additions & 20 deletions ports/raspberrypi/audio_dma.c
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Original file line number Diff line number Diff line change
Expand Up @@ -486,28 +486,14 @@ void __not_in_flash_func(isr_dma_0)(void) {
dma->channels_to_load_mask |= mask;
background_callback_add(&dma->callback, dma_callback_fun, (void *)dma);
}
if (MP_STATE_PORT(background_pio)[i] != NULL) {
rp2pio_statemachine_obj_t *pio = MP_STATE_PORT(background_pio)[i];
rp2pio_statemachine_dma_complete_write(pio, i);
}
}
}

void __not_in_flash_func(isr_dma_1)(void) {
for (size_t i = 0; i < NUM_DMA_CHANNELS; i++) {
uint32_t mask = 1 << i;
if ((dma_hw->intr & mask) == 0) {
continue;
}
// acknowledge interrupt early. Doing so late means that you could lose an
// interrupt if the buffer is very small and the DMA operation
// completed by the time callback_add() / dma_complete() returned. This
// affected PIO continuous write more than audio.
dma_hw->ints1 = mask;
if (MP_STATE_PORT(background_pio)[i] != NULL) {
rp2pio_statemachine_obj_t *pio = MP_STATE_PORT(background_pio)[i];
if (MP_STATE_PORT(background_pio_read)[i] != NULL) {
rp2pio_statemachine_obj_t *pio = MP_STATE_PORT(background_pio_read)[i];
rp2pio_statemachine_dma_complete_read(pio, i);
}
if (MP_STATE_PORT(background_pio_write)[i] != NULL) {
rp2pio_statemachine_obj_t *pio = MP_STATE_PORT(background_pio_write)[i];
rp2pio_statemachine_dma_complete_write(pio, i);
}
}
}

Expand Down
17 changes: 9 additions & 8 deletions ports/raspberrypi/common-hal/rp2pio/StateMachine.c
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Original file line number Diff line number Diff line change
Expand Up @@ -96,7 +96,7 @@ static void rp2pio_statemachine_clear_dma_write(int pio_index, int sm) {
if (!dma_hw->inte0) {
irq_set_mask_enabled(1 << DMA_IRQ_0, false);
}
MP_STATE_PORT(background_pio)[channel_write] = NULL;
MP_STATE_PORT(background_pio_write)[channel_write] = NULL;
dma_channel_abort(channel_write);
dma_channel_unclaim(channel_write);
}
Expand All @@ -111,7 +111,7 @@ static void rp2pio_statemachine_clear_dma_read(int pio_index, int sm) {
if (!dma_hw->inte0) {
irq_set_mask_enabled(1 << DMA_IRQ_0, false);
}
MP_STATE_PORT(background_pio)[channel_read] = NULL;
MP_STATE_PORT(background_pio_read)[channel_read] = NULL;
dma_channel_abort(channel_read);
dma_channel_unclaim(channel_read);
}
Expand Down Expand Up @@ -1229,7 +1229,7 @@ bool common_hal_rp2pio_statemachine_background_write(rp2pio_statemachine_obj_t *

// Acknowledge any previous pending interrupt
dma_hw->ints0 |= 1u << channel_write;
MP_STATE_PORT(background_pio)[channel_write] = self;
MP_STATE_PORT(background_pio_write)[channel_write] = self;
dma_hw->inte0 |= 1u << channel_write;

irq_set_mask_enabled(1 << DMA_IRQ_0, true);
Expand Down Expand Up @@ -1392,10 +1392,10 @@ bool common_hal_rp2pio_statemachine_background_read(rp2pio_statemachine_obj_t *s

common_hal_mcu_disable_interrupts();
// Acknowledge any previous pending interrupt
dma_hw->ints1 |= 1u << channel_read;
MP_STATE_PORT(background_pio)[channel_read] = self;
dma_hw->inte1 |= 1u << channel_read;
irq_set_mask_enabled(1 << DMA_IRQ_1, true);
dma_hw->ints0 |= 1u << channel_read;
MP_STATE_PORT(background_pio_read)[channel_read] = self;
dma_hw->inte0 |= 1u << channel_read;
irq_set_mask_enabled(1 << DMA_IRQ_0, true);
dma_start_channel_mask((1u << channel_read));
common_hal_mcu_enable_interrupts();

Expand Down Expand Up @@ -1485,4 +1485,5 @@ mp_obj_t common_hal_rp2pio_statemachine_get_last_write(rp2pio_statemachine_obj_t

// Use a compile-time constant for MP_REGISTER_POINTER so the preprocessor will
// not split the expansion across multiple lines.
MP_REGISTER_ROOT_POINTER(mp_obj_t background_pio[enum_NUM_DMA_CHANNELS]);
MP_REGISTER_ROOT_POINTER(mp_obj_t background_pio_read[enum_NUM_DMA_CHANNELS]);
MP_REGISTER_ROOT_POINTER(mp_obj_t background_pio_write[enum_NUM_DMA_CHANNELS]);