V4L/DVB (11619): cx18: Simplify the work handler for outgoing mailbox commands

Simplify the way outgoing work handler gets scheduled to send empty buffers
back to the firmware for use.  Also reduced the memory required for scheduling
this outgoing work, by using a single, per stream work object.

Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 5 insertions, 77 deletions

diff --git a/drivers/media/video/cx18/cx18-streams.c b/drivers/media/video/cx18/cx18-streams.c
index e1934e9cfdc8..41a1b2618aac 100644
--- a/drivers/media/video/cx18/cx18-streams.c
+++ b/drivers/media/video/cx18/cx18-streams.c
@@ -124,6 +124,8 @@ static void cx18_stream_init(struct cx18 *cx, int type)
         cx18_queue_init(&s->q_busy);
         spin_lock_init(&s->q_full.lock);
         cx18_queue_init(&s->q_full);
+
+        INIT_WORK(&s->out_work_order, cx18_out_work_handler);
 }
 
 static int cx18_prep_dev(struct cx18 *cx, int type)
@@ -477,86 +479,12 @@ void _cx18_stream_load_fw_queue(struct cx18_stream *s)
                  && q == &s->q_busy);
 }
 
-static inline
-void free_out_work_order(struct cx18_out_work_order *order)
-{
-        atomic_set(&order->pending, 0);
-}
-
 void cx18_out_work_handler(struct work_struct *work)
 {
-        struct cx18_out_work_order *order =
-                        container_of(work, struct cx18_out_work_order, work);
-        struct cx18_stream *s = order->s;
-        struct cx18_buffer *buf = order->buf;
-
-        free_out_work_order(order);
-
-        if (buf == NULL)
-                _cx18_stream_load_fw_queue(s);
-        else
-                _cx18_stream_put_buf_fw(s, buf);
-}
-
-static
-struct cx18_out_work_order *alloc_out_work_order(struct cx18 *cx)
-{
-        int i;
-        struct cx18_out_work_order *order = NULL;
-
-        for (i = 0; i < CX18_MAX_OUT_WORK_ORDERS; i++) {
-                /*
-                 * We need "pending" to be atomic to inspect & set its contents
-                 * 1. "pending" is only set to 1 here, but needs multiple access
-                 * protection
-                 * 2. work handler threads only clear "pending" and only
-                 * on one, particular work order at a time, per handler thread.
-                 */
-                if (atomic_add_unless(&cx->out_work_order[i].pending, 1, 1)) {
-                        order = &cx->out_work_order[i];
-                        break;
-                }
-        }
-        return order;
-}
-
-struct cx18_queue *cx18_stream_put_buf_fw(struct cx18_stream *s,
-                                          struct cx18_buffer *buf)
-{
-        struct cx18 *cx = s->cx;
-        struct cx18_out_work_order *order;
-
-        order = alloc_out_work_order(cx);
-        if (order == NULL) {
-                CX18_DEBUG_WARN("No blank, outgoing-mailbox, deferred-work, "
-                                "order forms available; sending buffer %u back "
-                                "to the firmware immediately for stream %s\n",
-                                buf->id, s->name);
-                return _cx18_stream_put_buf_fw(s, buf);
-        }
-        order->s = s;
-        order->buf = buf;
-        queue_work(cx->out_work_queue, &order->work);
-        return NULL;
-}
-
-void cx18_stream_load_fw_queue(struct cx18_stream *s)
-{
-        struct cx18 *cx = s->cx;
-        struct cx18_out_work_order *order;
+        struct cx18_stream *s =
+                         container_of(work, struct cx18_stream, out_work_order);
 
-        order = alloc_out_work_order(cx);
-        if (order == NULL) {
-                CX18_DEBUG_WARN("No blank, outgoing-mailbox, deferred-work, "
-                                "order forms available; filling the firmware "
-                                "buffer queue immediately for stream %s\n",
-                                s->name);
-                _cx18_stream_load_fw_queue(s);
-                return;
-        }
-        order->s = s;
-        order->buf = NULL; /* Indicates to load the fw queue */
-        queue_work(cx->out_work_queue, &order->work);
+        _cx18_stream_load_fw_queue(s);
 }
 
 int cx18_start_v4l2_encode_stream(struct cx18_stream *s)