// SPDX-License-Identifier: GPL-2.0#include <linux/kthread.h>#include <linux/wait.h> #include "spk_types.h"#include "speakup.h"#include "spk_priv.h" DECLARE_WAIT_QUEUE_HEAD(speakup_event);EXPORT_SYMBOL_GPL(speakup_event); int speakup_thread(void *data){	unsigned long flags;	int should_break;	struct bleep our_sound; 	our_sound.active = 0;	our_sound.freq = 0;	our_sound.jiffies = 0; 	mutex_lock(&spk_mutex);	while (1) {		DEFINE_WAIT(wait); 		while (1) {			spin_lock_irqsave(&speakup_info.spinlock, flags);			our_sound = spk_unprocessed_sound;			spk_unprocessed_sound.active = 0;			prepare_to_wait(&speakup_event, &wait,					TASK_INTERRUPTIBLE);			should_break = kthread_should_stop() ||				our_sound.active ||				(synth && synth->catch_up && synth->alive &&					(speakup_info.flushing ||					!synth_buffer_empty()));			spin_unlock_irqrestore(&speakup_info.spinlock, flags);			if (should_break)				break;			mutex_unlock(&spk_mutex);			schedule();			mutex_lock(&spk_mutex);		}		finish_wait(&speakup_event, &wait);		if (kthread_should_stop())			break; 		if (our_sound.active)			kd_mksound(our_sound.freq, our_sound.jiffies);		if (synth && synth->catch_up && synth->alive) {			/*			 * It is up to the callee to take the lock, so that it			 * can sleep whenever it likes			 */			synth->catch_up(synth);		} 		speakup_start_ttys();	}	mutex_unlock(&spk_mutex);	return 0;}