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
  25                 while (1) {
  26                         spin_lock_irqsave(&speakup_info.spinlock, flags);
  27                         our_sound = spk_unprocessed_sound;
  28                         spk_unprocessed_sound.active = 0;
  29                         prepare_to_wait(&speakup_event, &wait,
  30                                         TASK_INTERRUPTIBLE);
  31                         should_break = kthread_should_stop() ||
  32                                 our_sound.active ||
  33                                 (synth && synth->catch_up && synth->alive &&
  34                                         (speakup_info.flushing ||
  35                                         !synth_buffer_empty()));
  36                         spin_unlock_irqrestore(&speakup_info.spinlock, flags);
  37                         if (should_break)
  38                                 break;
  39                         mutex_unlock(&spk_mutex);
  40                         schedule();
  41                         mutex_lock(&spk_mutex);
  42                 }
  43                 finish_wait(&speakup_event, &wait);
  44                 if (kthread_should_stop())
  45                         break;
  46
  47                 if (our_sound.active)
  48                         kd_mksound(our_sound.freq, our_sound.jiffies);
  49                 if (synth && synth->catch_up && synth->alive) {
  50                         /*
  51                          * It is up to the callee to take the lock, so that it
  52                          * can sleep whenever it likes
  53                          */
  54                         synth->catch_up(synth);
  55                 }
  56
  57                 speakup_start_ttys();
  58         }
  59         mutex_unlock(&spk_mutex);
  60         return 0;
  61 }