LXR linux/drivers/accessibility/speakup/thread.c

   1// SPDX-License-Identifier: GPL-2.0
   2#include <linux/kthread.h>
   3#include <linux/wait.h>
   4
   5#include "spk_types.h"
   6#include "speakup.h"
   7#include "spk_priv.h"
   8
   9DECLARE_WAIT_QUEUE_HEAD(speakup_event);
  10EXPORT_SYMBOL_GPL(speakup_event);
  11
  12int speakup_thread(void *data)
  13{
  14        unsigned long flags;
  15        int should_break;
  16        struct bleep our_sound;
  17
  18        our_sound.active = 0;
  19        our_sound.freq = 0;
  20        our_sound.jiffies = 0;
  21
  22        mutex_lock(&spk_mutex);
  23        while (1) {
  24                DEFINE_WAIT(wait);
  25
  26                while (1) {
  27                        spin_lock_irqsave(&speakup_info.spinlock, flags);
  28                        our_sound = spk_unprocessed_sound;
  29                        spk_unprocessed_sound.active = 0;
  30                        prepare_to_wait(&speakup_event, &wait,
  31                                        TASK_INTERRUPTIBLE);
  32                        should_break = kthread_should_stop() ||
  33                                our_sound.active ||
  34                                (synth && synth->catch_up && synth->alive &&
  35                                        (speakup_info.flushing ||
  36                                        !synth_buffer_empty()));
  37                        spin_unlock_irqrestore(&speakup_info.spinlock, flags);
  38                        if (should_break)
  39                                break;
  40                        mutex_unlock(&spk_mutex);
  41                        schedule();
  42                        mutex_lock(&spk_mutex);
  43                }
  44                finish_wait(&speakup_event, &wait);
  45                if (kthread_should_stop())
  46                        break;
  47
  48                if (our_sound.active)
  49                        kd_mksound(our_sound.freq, our_sound.jiffies);
  50                if (synth && synth->catch_up && synth->alive) {
  51                        /*
  52                         * It is up to the callee to take the lock, so that it
  53                         * can sleep whenever it likes
  54                         */
  55                        synth->catch_up(synth);
  56                }
  57
  58                speakup_start_ttys();
  59        }
  60        mutex_unlock(&spk_mutex);
  61        return 0;
  62}
  63