From 06a7bf967c58644a0d341764994bdcc9253b4527 Mon Sep 17 00:00:00 2001 From: Andrew Leech Date: Wed, 1 Nov 2023 11:06:10 +1100 Subject: [PATCH] esp32/usb: Wake main thread when USB receives data. This improves (decreases) the latency on stdin, on SoCs with built-in USB and using TinyUSB, like S2 and S3. Signed-off-by: Andrew Leech --- ports/esp32/usb.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/ports/esp32/usb.c b/ports/esp32/usb.c index 2e417755c9..316482e189 100644 --- a/ports/esp32/usb.c +++ b/ports/esp32/usb.c @@ -40,8 +40,10 @@ static uint8_t usb_rx_buf[CONFIG_TINYUSB_CDC_RX_BUFSIZE]; +// This is called from FreeRTOS task "tusb_tsk" in espressif__esp_tinyusb (not an ISR). static void usb_callback_rx(int itf, cdcacm_event_t *event) { - // TODO: what happens if more chars come in during this function, are they lost? + // espressif__esp_tinyusb places tinyusb rx data onto freertos ringbuffer which + // this function forwards onto our stdin_ringbuf. for (;;) { size_t len = 0; esp_err_t ret = tinyusb_cdcacm_read(itf, usb_rx_buf, sizeof(usb_rx_buf), &len); @@ -58,6 +60,7 @@ static void usb_callback_rx(int itf, cdcacm_event_t *event) { ringbuf_put(&stdin_ringbuf, usb_rx_buf[i]); } } + mp_hal_wake_main_task(); } }