fix(midi2): fix discovery response racing Signed-off-by: HiFiPhile <admin@hifiphile.com>
diff --git a/src/class/midi/midi2_device.c b/src/class/midi/midi2_device.c index 369d380..b0a9e25 100644 --- a/src/class/midi/midi2_device.c +++ b/src/class/midi/midi2_device.c
@@ -112,7 +112,10 @@ uint8_t nego_pending_fb_filter; uint8_t nego_pending_fb_num; // block requested by the pending discovery, 0xFF = all uint8_t nego_pending_fb_next; // next block index to reply for + bool nego_pending_fb_restart; // restart after the active FB name when requests merge + uint16_t nego_text_status; // text reply owning nego_text_offset, 0 = none uint16_t nego_text_offset; // progress into the text reply being sent + uint8_t nego_text_index; // Function Block index for an active FB name /*------------- From this point, data is not cleared by bus reset -------------*/ struct { @@ -444,29 +447,85 @@ _nego_send_ump(p_midi, msg, 4); } +static void _nego_clear_pending(midi2d_interface_t* p_midi) { + p_midi->nego_pending_ep_filter = 0; + p_midi->nego_pending_fb_filter = 0; + p_midi->nego_pending_fb_num = 0; + p_midi->nego_pending_fb_next = 0; + p_midi->nego_pending_fb_restart = false; + p_midi->nego_text_status = 0; + p_midi->nego_text_offset = 0; + p_midi->nego_text_index = 0; +} + +static const char* _nego_text_cb(midi2d_interface_t* p_midi, uint16_t status, uint8_t index) { + const uint8_t itf = _itf_idx(p_midi); + switch (status) { + case STREAM_EP_NAME: return tud_midi2_ep_name_cb(itf); + case STREAM_PROD_INSTANCE_ID: return tud_midi2_product_id_cb(itf); + case STREAM_FB_NAME: return tud_midi2_fb_name_cb(itf, index); + default: return NULL; + } +} + +// Send or resume one text reply. While it is incomplete, its status and index +// identify the sole owner of nego_text_offset so another discovery request +// cannot resume a different string from the same offset. +static bool _nego_send_text(midi2d_interface_t* p_midi, uint16_t status, uint8_t index) { + const char* text = _nego_text_cb(p_midi, status, index); + const uint16_t len = text ? (uint16_t) strlen(text) : 0; + + p_midi->nego_text_status = status; + p_midi->nego_text_index = index; + p_midi->nego_text_offset = _nego_send_stream_text(p_midi, status, status == STREAM_FB_NAME, + index, text, p_midi->nego_text_offset); + if (p_midi->nego_text_offset < len) return false; + + p_midi->nego_text_status = 0; + p_midi->nego_text_offset = 0; + p_midi->nego_text_index = 0; + return true; +} + // Send pending discovery replies, one whole reply at a time and only when the // TX FIFO can take it. A full-filter Endpoint Discovery asks for more bytes // than the default FIFO holds; replies that do not fit stay pending and are // retried from the TX complete path, paced by the transfer flow. static void _nego_send_pending(midi2d_interface_t* p_midi) { tu_fifo_t* tx_ff = &p_midi->ep_stream.tx.ff; - const uint8_t itf = _itf_idx(p_midi); + + // An incomplete text sequence must finish before any newly arrived request + // is serviced; otherwise its Continue/End packets could be attached to a + // different Endpoint or Function Block string. + if (p_midi->nego_text_status) { + const uint16_t status = p_midi->nego_text_status; + const uint8_t index = p_midi->nego_text_index; + if (!_nego_send_text(p_midi, status, index)) return; + + if (status == STREAM_FB_NAME) { + if (p_midi->nego_pending_fb_restart) { + p_midi->nego_pending_fb_next = 0; + p_midi->nego_pending_fb_restart = false; + } else { + p_midi->nego_pending_fb_next++; + } + } else { + const uint8_t bit = (status == STREAM_EP_NAME) ? 0x04 : 0x08; + p_midi->nego_pending_ep_filter &= (uint8_t) ~bit; + } + } while (p_midi->nego_pending_ep_filter) { const uint8_t bit = (uint8_t)(p_midi->nego_pending_ep_filter & (uint8_t)(-p_midi->nego_pending_ep_filter)); - const char* text = NULL; uint16_t status = 0; switch (bit) { - case 0x04: text = tud_midi2_ep_name_cb(itf); status = STREAM_EP_NAME; break; - case 0x08: text = tud_midi2_product_id_cb(itf); status = STREAM_PROD_INSTANCE_ID; break; + case 0x04: status = STREAM_EP_NAME; break; + case 0x08: status = STREAM_PROD_INSTANCE_ID; break; default: break; } - if (text != NULL) { - p_midi->nego_text_offset = _nego_send_stream_text(p_midi, status, false, 0, text, - p_midi->nego_text_offset); - if (p_midi->nego_text_offset < (uint16_t) strlen(text)) return; // resume on TX complete - p_midi->nego_text_offset = 0; + if (status != 0) { + if (!_nego_send_text(p_midi, status, 0)) return; } else { if (tu_fifo_remaining(tx_ff) < 16) return; switch (bit) { @@ -491,11 +550,7 @@ _nego_send_fb_info(p_midi, f); } if (p_midi->nego_pending_fb_filter & 0x02) { - const char* name = tud_midi2_fb_name_cb(itf, f); - p_midi->nego_text_offset = _nego_send_stream_text(p_midi, STREAM_FB_NAME, true, f, name, - p_midi->nego_text_offset); - if (name != NULL && p_midi->nego_text_offset < (uint16_t) strlen(name)) return; - p_midi->nego_text_offset = 0; + if (!_nego_send_text(p_midi, STREAM_FB_NAME, f)) return; } p_midi->nego_pending_fb_next++; } @@ -541,16 +596,21 @@ case STREAM_FB_DISCOVERY: { const uint8_t req_num = (uint8_t)((words[0] >> 8) & 0xFF); + const uint8_t req_filter = (uint8_t)(words[0] & 0x03); // Merge with a pending request: repeating a Function Block Info is allowed // at any time, losing a requested one is not. - if (p_midi->nego_pending_fb_filter && p_midi->nego_pending_fb_num != req_num) { - p_midi->nego_pending_fb_num = 0xFF; - p_midi->nego_pending_fb_next = 0; + if (req_filter && p_midi->nego_pending_fb_filter) { + if (p_midi->nego_pending_fb_num != req_num) p_midi->nego_pending_fb_num = 0xFF; + if (p_midi->nego_text_status == STREAM_FB_NAME) { + p_midi->nego_pending_fb_restart = true; + } else { + p_midi->nego_pending_fb_next = 0; + } } else if (!p_midi->nego_pending_fb_filter) { p_midi->nego_pending_fb_num = req_num; p_midi->nego_pending_fb_next = 0; } - p_midi->nego_pending_fb_filter |= (uint8_t)(words[0] & 0x03); // bit 0: FB Info, bit 1: FB Name + p_midi->nego_pending_fb_filter |= req_filter; // bit 0: FB Info, bit 1: FB Name _nego_send_pending(p_midi); break; } @@ -861,6 +921,7 @@ tu_edpt_stream_clear(&p_midi->ep_stream.rx); tu_fifo_clear(&p_midi->ep_stream.tx.ff); + _nego_clear_pending(p_midi); if (alt == 1) { p_midi->negotiated = false;