commit ac8f277e5ad5c678c996c41d9bfd5ee72e525fee
author Peter Harper <77111776+peterharperuk@users.noreply.github.com> Sun May 19 00:59:47 2024 +0100
committer GitHub <noreply@github.com> Sat May 18 18:59:47 2024 -0500
tree 4fb5d9d91d6f2fd8a242f2ba84b7ed5c61419854
parent fcd5333f6bb13b883d108a316c4d9cd056df9b67

Fix stdio_set_chars_available_callback for usb (#1649)

When you get a callback to tell you a character is available, you should
be able to call getchar_timeout_us, but it's not working for USB

Fixes #1603

Co-authored-by: Andrew Gordon <arg@gordondesign.ltd.uk>

src/rp2_common/pico_stdio_usb/stdio_usb.c

diff --git a/src/rp2_common/pico_stdio_usb/stdio_usb.c b/src/rp2_common/pico_stdio_usb/stdio_usb.c
index 0dc8d6d..2895be7 100644
--- a/src/rp2_common/pico_stdio_usb/stdio_usb.c
+++ b/src/rp2_common/pico_stdio_usb/stdio_usb.c
@@ -57,7 +57,13 @@
 static void low_priority_worker_irq(void) {
     if (mutex_try_enter(&stdio_usb_mutex, NULL)) {
         tud_task();
+#if PICO_STDIO_USB_SUPPORT_CHARS_AVAILABLE_CALLBACK
+        uint32_t chars_avail = tud_cdc_available();
+#endif
         mutex_exit(&stdio_usb_mutex);
+#if PICO_STDIO_USB_SUPPORT_CHARS_AVAILABLE_CALLBACK
+        if (chars_avail && chars_available_callback) chars_available_callback(chars_available_param);
+#endif
     } else {
         // if the mutex is already owned, then we are in non IRQ code in this file.
         //
@@ -147,12 +153,6 @@
 }
 
 #if PICO_STDIO_USB_SUPPORT_CHARS_AVAILABLE_CALLBACK
-void tud_cdc_rx_cb(__unused uint8_t itf) {
-    if (chars_available_callback) {
-        usbd_defer_func(chars_available_callback, chars_available_param, false);
-    }
-}
-
 void stdio_usb_set_chars_available_callback(void (*fn)(void*), void *param) {
     chars_available_callback = fn;
     chars_available_param = param;