static int find_output_space(int dev, char **buf, int *size)
{
struct audio_operations *adev = audio_devs[dev];
struct dma_buffparms *dmap = adev->dmap_out;
unsigned long flags;
unsigned long active_offs;
long len, offs;
int maxfrags;
int occupied_bytes = (dmap->user_counter % dmap->fragment_size);
*buf = dmap->raw_buf;
if (!(maxfrags = DMAbuf_space_in_queue(dev)) && !occupied_bytes)
return 0;
save_flags(flags);
cli();
#ifdef BE_CONSERVATIVE
active_offs = dmap->byte_counter + dmap->qhead * dmap->fragment_size;
#else
active_offs = DMAbuf_get_buffer_pointer(dev, dmap, DMODE_OUTPUT);
/* Check for pointer wrapping situation */
if (active_offs < 0 || active_offs >= dmap->bytes_in_use)
active_offs = 0;
active_offs += dmap->byte_counter;
#endif
offs = (dmap->user_counter % dmap->bytes_in_use) & ~SAMPLE_ROUNDUP;
if (offs < 0 || offs >= dmap->bytes_in_use) {
restore_flags(flags);
printk(KERN_ERR "Sound: Got unexpected offs %ld. Giving up.\n", offs);
printk("Counter = %ld, bytes=%d\n", dmap->user_counter, dmap->bytes_in_use);
return 0;
}
*buf = dmap->raw_buf + offs;
len = active_offs + dmap->bytes_in_use - dmap->user_counter; /* Number of unused bytes in buffer */
if ((offs + len) > dmap->bytes_in_use)
len = dmap->bytes_in_use - offs;
if (len < 0) {
restore_flags(flags);
return 0;
}
if (len > ((maxfrags * dmap->fragment_size) - occupied_bytes))
len = (maxfrags * dmap->fragment_size) - occupied_bytes;
*size = len & ~SAMPLE_ROUNDUP;
restore_flags(flags);
return (*size > 0);
}
static unsigned int poll_output(struct file * file, int dev, poll_table *wait)
{
struct audio_operations *adev = audio_devs[dev];
struct dma_buffparms *dmap = adev->dmap_out;
if (!(adev->open_mode & OPEN_WRITE))
return 0;
if (dmap->mapping_flags & DMA_MAP_MAPPED) {
if (dmap->qlen)
return POLLOUT | POLLWRNORM;
return 0;
}
if (dmap->dma_mode == DMODE_INPUT)
return 0;
if (dmap->dma_mode == DMODE_NONE)
return POLLOUT | POLLWRNORM;
if (!DMAbuf_space_in_queue(dev))
return 0;
return POLLOUT | POLLWRNORM;
}
