static ssize_t rd_read(struct file *file, char __user *buf,
size_t sz, loff_t *ppos)
{
struct msm_rd_state *rd = file->private_data;
struct circ_buf *fifo = &rd->fifo;
const char *fptr = &fifo->buf[fifo->tail];
int n = 0, ret = 0;
mutex_lock(&rd->read_lock);
ret = wait_event_interruptible(rd->fifo_event,
circ_count(&rd->fifo) > 0);
if (ret)
goto out;
n = min_t(int, sz, circ_count_to_end(&rd->fifo));
ret = copy_to_user(buf, fptr, n);
if (ret)
goto out;
fifo->tail = (fifo->tail + n) & (BUF_SZ - 1);
*ppos += n;
wake_up_all(&rd->fifo_event);
out:
mutex_unlock(&rd->read_lock);
if (ret)
return ret;
return n;
}
static inline bool __acpi_aml_readable(struct circ_buf *circ, unsigned long flag)
{
/*
* Another read is not in progress and there is data in buffer
* available for read.
*/
if (!(acpi_aml_io.flags & flag) && circ_count(circ))
return true;
return false;
}
