esp32/usb: Wake main thread when usb receives data.

Andrew Leech · Andrew Leech · commit 642affc7e336 · 2023-11-01T13:16:41.000+11:00
This improves latency on stdin.

Signed-off-by: Andrew Leech &lt;andrew.leech@planetinnovation.com.au&gt;
diff --git a/ports/esp32/usb.c b/ports/esp32/usb.c
@@ -41,7 +41,8 @@
 static uint8_t usb_rx_buf[CONFIG_TINYUSB_CDC_RX_BUFSIZE];
 
 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?
+    // IDF places tinyusb rx data onto freertos ringbuffer which this function
+    // forwards onto the 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 +59,7 @@ static void usb_callback_rx(int itf, cdcacm_event_t *event) {
                 ringbuf_put(&stdin_ringbuf, usb_rx_buf[i]);
             }
         }
+        xTaskNotifyGive(mp_main_task_handle);
     }
 }
 

Original file line number	Diff line number	Diff line change
`@@ -41,7 +41,8 @@`
`41`	`41`	`static uint8_t usb_rx_buf[CONFIG_TINYUSB_CDC_RX_BUFSIZE];`
`42`	`42`
`43`	`43`	`static void usb_callback_rx(int itf, cdcacm_event_t *event) {`
`44`		`- // TODO: what happens if more chars come in during this function, are they lost?`
	`44`	`+ // IDF places tinyusb rx data onto freertos ringbuffer which this function`
	`45`	`+ // forwards onto the stdin_ringbuf`
`45`	`46`	`for (;;) {`
`46`	`47`	`size_t len = 0;`
`47`	`48`	`esp_err_t ret = tinyusb_cdcacm_read(itf, usb_rx_buf, sizeof(usb_rx_buf), &len);`
`@@ -58,6 +59,7 @@ static void usb_callback_rx(int itf, cdcacm_event_t *event) {`
`58`	`59`	`ringbuf_put(&stdin_ringbuf, usb_rx_buf[i]);`
`59`	`60`	`}`
`60`	`61`	`}`
	`62`	`+ xTaskNotifyGive(mp_main_task_handle);`
`61`	`63`	`}`
`62`	`64`	`}`
`63`	`65`