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audio: treat SuperSpeed as microframed in the feedback computation

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Two halves of the same computation disagreed once TUSB_SPEED_SUPER existed.
frame_div and k already resolve SUPER to the microframe form by testing
"== TUSB_SPEED_FULL", but the fifo_count rate constants and the feedback
interval tested "== TUSB_SPEED_HIGH", so at SuperSpeed the constants stayed 8x
too large and tud_audio_feedback_interval_isr() fired 8x too rarely. Latent
today - no DCD serves SuperSpeed isochronous yet - but it is shared class code.
This commit is contained in:
hathach
2026-08-16 04:55:18 +07:00
parent 708c4f9fb5
commit d8e4d72c07
1 changed files with 7 additions and 4 deletions
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11
src/class/audio/audio_device.c
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@ -1576,8 +1576,10 @@ static bool audiod_fb_params_prepare(uint8_t func_id, uint8_t alt) {
audio->feedback.compute.fifo_count.nom_value = nominal;
audio->feedback.compute.fifo_count.rate_const[0] = (uint16_t) ((audio->feedback.max_value - nominal) / fifo_threshold);
audio->feedback.compute.fifo_count.rate_const[1] = (uint16_t) ((nominal - audio->feedback.min_value) / fifo_threshold);
// On HS feedback is more sensitive since packet size can vary every MSOF, could cause instability
if (tud_speed_get() == TUSB_SPEED_HIGH) {
// On HS feedback is more sensitive since packet size can vary every MSOF, could cause
// instability. SuperSpeed is microframed too, so test "not full speed" rather than
// "== high speed" - matching frame_div/k above, which already resolve SUPER that way.
if (tud_speed_get() != TUSB_SPEED_FULL) {
audio->feedback.compute.fifo_count.rate_const[0] /= 8;
audio->feedback.compute.fifo_count.rate_const[1] /= 8;
}
@ -1637,8 +1639,9 @@ TU_ATTR_FAST_FUNC void audiod_sof_isr(uint8_t rhport, uint32_t frame_count) {
audiod_function_t *audio = &_audiod_fct[i];
if (audio->ep_fb != 0) {
// HS shift need to be adjusted since SOF event is generated for frame only
uint8_t const hs_adjust = (TUSB_SPEED_HIGH == tud_speed_get()) ? 3 : 0;
// HS shift need to be adjusted since SOF event is generated for frame only. SuperSpeed is
// microframed as well, so the adjustment applies to any speed above full.
uint8_t const hs_adjust = (TUSB_SPEED_FULL == tud_speed_get()) ? 0 : 3;
uint32_t const interval = 1UL << (audio->feedback.frame_shift - hs_adjust);
if (0 == (frame_count & (interval - 1))) {
tud_audio_feedback_interval_isr(i, frame_count, audio->feedback.frame_shift);