avld/bad.patch

   1 --- video_device.c.original     2009-02-02 16:34:08.000000000 +0800
   2 +++ video_device.c      2009-02-02 16:32:10.000000000 +0800
   3 @@ -26,7 +26,7 @@
   4  #include <media/v4l2-ioctl.h>
   5  #endif
   6
   7 -/*#define DEBUG*/
   8 +//#define DEBUG
   9
  10  #define KERNEL_PREFIX "AVLD device: " /* Prefix of each kernel message */
  11  #define VID_DUMMY_DEVICE 0 /* The type of device we create */
  12 @@ -456,14 +456,51 @@
  13                 printk(KERNEL_PREFIX "entering v4l_read()\n");
  14         #endif
  15
  16 +       int waiting_time;
  17 +       struct timeval current_time;
  18
  19         // if input size superior to the buffered image size
  20         if (count > BUFFER_SIZE) {
  21                 printk(KERNEL_PREFIX "ERROR : you are attempting to read too much data : %d/%lu\n",count,BUFFER_SIZE);
  22                 return -EINVAL;
  23         }
  24 -       memcpy(buf,image,count*sizeof(char));
  25 -
  26 +       copy_to_user(buf,image,count*sizeof(char));
  27 +
  28 +       // Wait to simulate FPS if necessary
  29 +       #ifdef DEBUG
  30 +               printk(KERNEL_PREFIX "waiting v4l_read() : %d - %ld\n",count,BUFFER_SIZE);
  31 +       #endif
  32 +       if ( fps > 0 ) {
  33 +               do_gettimeofday(&current_time);
  34 +               //printk(KERNEL_PREFIX "t2=%d.%d - t1=%d.%d\n",current_time.tv_sec,current_time.tv_usec,timer.tv_sec,timer.tv_usec);
  35 +
  36 +               // Compute waiting_time
  37 +               waiting_time = HZ/fps - HZ*( (current_time.tv_sec-timer.tv_sec)*USEC_PER_SEC  +  (current_time.tv_usec-timer.tv_usec)  )/USEC_PER_SEC;
  38 +               //waiting_time = MSEC_PER_SEC/fps - ( (current_time.tv_sec-timer.tv_sec)*MSEC_PER_SEC  +  (current_time.tv_usec-timer.tv_usec)/USEC_PER_MSEC  );
  39 +
  40 +               // waits
  41 +               if (waiting_time > 0) {
  42 +                       // solution 1
  43 +                       interruptible_sleep_on_timeout (&wait,waiting_time);
  44 +
  45 +                       // solution 2
  46 +                       //set_current_state(TASK_INTERRUPTIBLE);
  47 +                       //schedule_timeout(waiting_time);
  48 +
  49 +                       // solution 3
  50 +                       //msleep_interruptible(waiting_time);
  51 +               }
  52 +
  53 +               do_gettimeofday(&timer);
  54 +       }
  55 +       // Wait reader before continue
  56 +       else if ( fps < 0 ) {
  57 +               #ifdef DEBUG
  58 +                       printk (KERN_INFO "fps value : %d\n",fps);
  59 +               #endif
  60 +               mutex_lock_interruptible(&lock);
  61 +       }
  62 +
  63         #ifdef DEBUG
  64                 printk(KERNEL_PREFIX "leaving v4l_read() : %d - %ld\n",count,BUFFER_SIZE);
  65         #endif