drivers/staging/speakup/thread.c

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