From b73df6c22e4743f9232f7922fe2cf0fbd05a3a2e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?C=C3=A9dric=20Berger?= <cedric@precidata.com>
Date: Sun, 1 Feb 2026 21:08:03 +0100
Subject: [PATCH 1/2] Limit events processed by tud_task_ext() / tuh_task_ext()

---
 src/device/usbd.c |  9 +++++++--
 src/host/usbh.c   |  9 +++++++--
 src/tusb_option.h | 10 ++++++++++
 3 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/src/device/usbd.c b/src/device/usbd.c
index 1e21c667a..8f3a7a226 100644
--- a/src/device/usbd.c
+++ b/src/device/usbd.c
@@ -666,8 +666,13 @@ void tud_task_ext(uint32_t timeout_ms, bool in_isr) {
     return;
   }
 
-  // Loop until there is no more events in the queue
-  while (1) {
+  // Loop until there are no more events in the queue or CFG_TUD_TASK_EVENTS_PER_RUN is reached
+  for (unsigned epr = 0;; epr++) {
+#if CFG_TUD_TASK_EVENTS_PER_RUN > 0
+    if (epr >= CFG_TUD_TASK_EVENTS_PER_RUN) {
+      TU_LOG_USBD("USBD event limit (" TU_XSTRING(CFG_TUD_TASK_EVENTS_PER_RUN) ") reached\r\n");
+    }
+#endif
     dcd_event_t event;
     if (!osal_queue_receive(_usbd_q, &event, timeout_ms)) {
       return;
diff --git a/src/host/usbh.c b/src/host/usbh.c
index a725b7c8b..cc99c0a53 100644
--- a/src/host/usbh.c
+++ b/src/host/usbh.c
@@ -599,8 +599,13 @@ void tuh_task_ext(uint32_t timeout_ms, bool in_isr) {
     return;
   }
 
-  // Loop until there is no more events in the queue
-  while (1) {
+  // Loop until there are no more events in the queue or CFG_TUH_TASK_EVENTS_PER_RUN is reached
+  for (unsigned epr = 0;; epr++) {
+#if CFG_TUH_TASK_EVENTS_PER_RUN > 0
+    if (epr >= CFG_TUH_TASK_EVENTS_PER_RUN) {
+      TU_LOG_USBH("USBH event limit (" TU_XSTRING(CFG_TUH_TASK_EVENTS_PER_RUN) ") reached\r\n");
+    }
+#endif
     hcd_event_t event;
     if (!osal_queue_receive(_usbh_q, &event, timeout_ms)) { return; }
 
diff --git a/src/tusb_option.h b/src/tusb_option.h
index abf5e0608..d34f2b710 100644
--- a/src/tusb_option.h
+++ b/src/tusb_option.h
@@ -560,6 +560,11 @@
   #define CFG_TUD_INTERFACE_MAX   16
 #endif
 
+// max events processed in one tud_task_ext() call, 0 for unlimited
+#ifndef CFG_TUD_TASK_EVENTS_PER_RUN
+  #define CFG_TUD_TASK_EVENTS_PER_RUN  16
+#endif
+
 // default to max hardware endpoint, but can be smaller to save RAM
 #ifndef CFG_TUD_ENDPPOINT_MAX
   #define CFG_TUD_ENDPPOINT_MAX   TUP_DCD_ENDPOINT_MAX
@@ -679,6 +684,11 @@
   #define CFG_TUH_MEM_DCACHE_LINE_SIZE CFG_TUSB_MEM_DCACHE_LINE_SIZE
 #endif
 
+// max events processed in one tuh_task_ext() call, 0 for unlimited
+#ifndef CFG_TUH_TASK_EVENTS_PER_RUN
+  #define CFG_TUH_TASK_EVENTS_PER_RUN  16
+#endif
+
 //------------- CLASS -------------//
 
 #ifndef CFG_TUH_HUB

From d2f1b1899d4dbdab2a5bfd822c3bbe5fc0ee8deb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?C=C3=A9dric=20Berger?= <cedric@precidata.com>
Date: Sun, 1 Feb 2026 22:29:52 +0100
Subject: [PATCH 2/2] Actually exit the loop in addition to logging.
 ENOTENOUGHCOFFEE

---
 src/device/usbd.c | 1 +
 src/host/usbh.c   | 1 +
 2 files changed, 2 insertions(+)

diff --git a/src/device/usbd.c b/src/device/usbd.c
index 8f3a7a226..cca4169d7 100644
--- a/src/device/usbd.c
+++ b/src/device/usbd.c
@@ -671,6 +671,7 @@ void tud_task_ext(uint32_t timeout_ms, bool in_isr) {
 #if CFG_TUD_TASK_EVENTS_PER_RUN > 0
     if (epr >= CFG_TUD_TASK_EVENTS_PER_RUN) {
       TU_LOG_USBD("USBD event limit (" TU_XSTRING(CFG_TUD_TASK_EVENTS_PER_RUN) ") reached\r\n");
+      break;
     }
 #endif
     dcd_event_t event;
diff --git a/src/host/usbh.c b/src/host/usbh.c
index cc99c0a53..41f41dcfb 100644
--- a/src/host/usbh.c
+++ b/src/host/usbh.c
@@ -604,6 +604,7 @@ void tuh_task_ext(uint32_t timeout_ms, bool in_isr) {
 #if CFG_TUH_TASK_EVENTS_PER_RUN > 0
     if (epr >= CFG_TUH_TASK_EVENTS_PER_RUN) {
       TU_LOG_USBH("USBH event limit (" TU_XSTRING(CFG_TUH_TASK_EVENTS_PER_RUN) ") reached\r\n");
+      break;
     }
 #endif
     hcd_event_t event;