[media] lirc_zilog: Don't acquire the rx->buf_lock in the poll() function
There is no need to take the rx->buf_lock in the the poll() function
as all the underling calls made on objects in the rx->buf lirc_buffer object
are protected by spinlocks.
Corrected a bad error return value in poll(): return POLLERR instead
of -ENODEV.
Added some comments to poll() for when, in the future, I forget what
poll() and poll_wait() are supposed to do.
[Jarod: minor debug spew fix]
Signed-off-by: Andy Walls <awalls@md.metrocast.net>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/staging/lirc/lirc_zilog.c b/drivers/staging/lirc/lirc_zilog.c
index 720ef67..695c3df 100644
--- a/drivers/staging/lirc/lirc_zilog.c
+++ b/drivers/staging/lirc/lirc_zilog.c
@@ -985,19 +985,26 @@
unsigned int ret;
dprintk("poll called\n");
- if (rx == NULL)
- return -ENODEV;
- mutex_lock(&rx->buf_lock);
+ if (rx == NULL) {
+ /*
+ * Revisit this, if our poll function ever reports writeable
+ * status for Tx
+ */
+ dprintk("poll result = POLLERR\n");
+ return POLLERR;
+ }
+ /*
+ * Add our lirc_buffer's wait_queue to the poll_table. A wake up on
+ * that buffer's wait queue indicates we may have a new poll status.
+ */
poll_wait(filep, &rx->buf.wait_poll, wait);
- dprintk("poll result = %s\n",
- lirc_buffer_empty(&rx->buf) ? "0" : "POLLIN|POLLRDNORM");
-
+ /* Indicate what ops could happen immediately without blocking */
ret = lirc_buffer_empty(&rx->buf) ? 0 : (POLLIN|POLLRDNORM);
- mutex_unlock(&rx->buf_lock);
+ dprintk("poll result = %s\n", ret ? "POLLIN|POLLRDNORM" : "none");
return ret;
}