DNM: Bluetooth: Host: Make bt rx thread never blocked

include/zephyr/kernel.h

@@ -3913,11 +3913,13 @@
 	/* Static work queue flags */
 	K_WORK_QUEUE_NO_YIELD_BIT = 8,
 	K_WORK_QUEUE_NO_YIELD = BIT(K_WORK_QUEUE_NO_YIELD_BIT),
+	K_WORK_QUEUE_NO_BLOCK_BIT = 9,
+	K_WORK_QUEUE_NO_BLOCK = BIT(K_WORK_QUEUE_NO_BLOCK_BIT),
 
 /**
  * INTERNAL_HIDDEN @endcond
  */
 	/* Transient work flags */
 
 	/** @brief Flag indicating a work item that is running under a work
 	 * queue thread.
@@ -4103,6 +4105,9 @@
 	 * essential thread.
 	 */
 	bool essential;
+
+	/** No Block by handler */
+	bool no_block;
 };
 
 /** @brief A structure used to hold work until it can be processed. */

include/zephyr/kernel/thread.h

@@ -252,6 +252,10 @@ struct z_poller {
 	uint8_t mode;
 };
 
+enum {
+	Z_THREAD_NO_BLOCK = 0,
+};
+
 /**
  * @ingroup thread_apis
  * Thread Structure
@@ -269,6 +273,9 @@ struct k_thread {
 	/** threads waiting in k_thread_join() */
 	_wait_q_t join_queue;
 
+	/** flags */
+	atomic_t flags;
+
 #if defined(CONFIG_POLL)
 	struct z_poller poller;
 #endif /* CONFIG_POLL */

kernel/sched.c

@@ -661,6 +661,10 @@ int z_pend_curr(struct k_spinlock *lock, k_spinlock_key_t key,
 #endif /* CONFIG_TIMESLICING && CONFIG_SWAP_NONATOMIC */
 	__ASSERT_NO_MSG(sizeof(_sched_spinlock) == 0 || lock != &_sched_spinlock);
 
+	if (atomic_test_bit(&(_current->flags), Z_THREAD_NO_BLOCK)) {
+		return -ECANCELED;
+	}
+
 	/* We do a "lock swap" prior to calling z_swap(), such that
 	 * the caller's lock gets released as desired.  But we ensure
 	 * that we hold the scheduler lock and leave local interrupts

kernel/work.c

@@ -625,7 +625,7 @@
 		struct k_work *work = NULL;
 		k_work_handler_t handler = NULL;
 		k_spinlock_key_t key = k_spin_lock(&lock);
-		bool yield;
+		bool yield, block;
 
 		/* Check for and prepare any new work. */
 		node = sys_slist_get(&queue->pending);
@@ -684,9 +684,20 @@
 
 		k_spin_unlock(&lock, key);
 
+		block = !flag_test(&queue->flags, K_WORK_QUEUE_NO_BLOCK_BIT);
+		if (!block) {
+			atomic_set_bit(&(k_work_queue_thread_get(queue)->flags),
+				       Z_THREAD_NO_BLOCK);
+		}
+
 		__ASSERT_NO_MSG(handler != NULL);
 		handler(work);
 
+		if (!block) {
+			atomic_clear_bit(&(k_work_queue_thread_get(queue)->flags),
+					 Z_THREAD_NO_BLOCK);
+		}
+
 		/* Mark the work item as no longer running and deal
 		 * with any cancellation and flushing issued while it
 		 * was running.  Clear the BUSY flag and optionally
@@ -747,6 +758,10 @@
 		flags |= K_WORK_QUEUE_NO_YIELD;
 	}
 
+	if ((cfg != NULL) && cfg->no_block) {
+		flags |= K_WORK_QUEUE_NO_BLOCK;
+	}
+
 	/* It hasn't actually been started yet, but all the state is in place
 	 * so we can submit things and once the thread gets control it's ready
 	 * to roll.

subsys/bluetooth/host/hci_core.c

@@ -4393,12 +4393,17 @@
 	k_fifo_init(&bt_dev.cmd_tx_queue);
 
 #if defined(CONFIG_BT_RECV_WORKQ_BT)
+	struct k_work_queue_config bt_workq_cfg = {
+		.name = "BT RX WQ",
+		.no_block = true,
+	};
+
 	/* RX thread */
 	k_work_queue_init(&bt_workq);
+
 	k_work_queue_start(&bt_workq, rx_thread_stack,
 			   CONFIG_BT_RX_STACK_SIZE,
-			   K_PRIO_COOP(CONFIG_BT_RX_PRIO), NULL);
-	k_thread_name_set(&bt_workq.thread, "BT RX WQ");
+			   K_PRIO_COOP(CONFIG_BT_RX_PRIO), &bt_workq_cfg);
 #endif
 
 #if DT_HAS_CHOSEN(zephyr_bt_hci)