[media] v4l/cx18: update workqueue usage

With cmwq, there's no reason to use separate out_work_queue.  Drop it
and use system_wq instead.  The in_work_queue needs to be ordered so
can't use one of the system wqs; however, as it isn't used to reclaim
memory, allocate the workqueue with alloc_ordered_workqueue() without
WQ_MEM_RECLAIM.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andy Walls <awalls@md.metrocast.net>
Acked-by: Andy Walls <awalls@md.metrocast.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/cx18/cx18-driver.c

@@ -664,7 +664,7 @@ static int __devinit cx18_create_in_workq(struct cx18 *cx)
 {
 	snprintf(cx->in_workq_name, sizeof(cx->in_workq_name), "%s-in",
 		 cx->v4l2_dev.name);
-	cx->in_work_queue = create_singlethread_workqueue(cx->in_workq_name);
+	cx->in_work_queue = alloc_ordered_workqueue(cx->in_workq_name, 0);
 	if (cx->in_work_queue == NULL) {
 		CX18_ERR("Unable to create incoming mailbox handler thread\n");
 		return -ENOMEM;
@@ -672,18 +672,6 @@ static int __devinit cx18_create_in_workq(struct cx18 *cx)
 	return 0;
 }
 
-static int __devinit cx18_create_out_workq(struct cx18 *cx)
-{
-	snprintf(cx->out_workq_name, sizeof(cx->out_workq_name), "%s-out",
-		 cx->v4l2_dev.name);
-	cx->out_work_queue = create_workqueue(cx->out_workq_name);
-	if (cx->out_work_queue == NULL) {
-		CX18_ERR("Unable to create outgoing mailbox handler threads\n");
-		return -ENOMEM;
-	}
-	return 0;
-}
-
 static void __devinit cx18_init_in_work_orders(struct cx18 *cx)
 {
 	int i;
@@ -710,15 +698,9 @@ static int __devinit cx18_init_struct1(struct cx18 *cx)
 	mutex_init(&cx->epu2apu_mb_lock);
 	mutex_init(&cx->epu2cpu_mb_lock);
 
-	ret = cx18_create_out_workq(cx);
-	if (ret)
-		return ret;
-
 	ret = cx18_create_in_workq(cx);
-	if (ret) {
-		destroy_workqueue(cx->out_work_queue);
+	if (ret)
 		return ret;
-	}
 
 	cx18_init_in_work_orders(cx);
 
@@ -1107,7 +1089,6 @@ free_mem:
 	release_mem_region(cx->base_addr, CX18_MEM_SIZE);
 free_workqueues:
 	destroy_workqueue(cx->in_work_queue);
-	destroy_workqueue(cx->out_work_queue);
 err:
 	if (retval == 0)
 		retval = -ENODEV;
@@ -1259,7 +1240,6 @@ static void cx18_remove(struct pci_dev *pci_dev)
 	cx18_halt_firmware(cx);
 
 	destroy_workqueue(cx->in_work_queue);
-	destroy_workqueue(cx->out_work_queue);
 
 	cx18_streams_cleanup(cx, 1);
 

drivers/media/video/cx18/cx18-driver.h

@@ -617,9 +617,6 @@ struct cx18 {
 	struct cx18_in_work_order in_work_order[CX18_MAX_IN_WORK_ORDERS];
 	char epu_debug_str[256]; /* CX18_EPU_DEBUG is rare: use shared space */
 
-	struct workqueue_struct *out_work_queue;
-	char out_workq_name[12]; /* "cx18-NN-out" */
-
 	/* i2c */
 	struct i2c_adapter i2c_adap[2];
 	struct i2c_algo_bit_data i2c_algo[2];

drivers/media/video/cx18/cx18-streams.h

@@ -42,8 +42,7 @@ static inline bool cx18_stream_enabled(struct cx18_stream *s)
 /* Related to submission of mdls to firmware */
 static inline void cx18_stream_load_fw_queue(struct cx18_stream *s)
 {
-	struct cx18 *cx = s->cx;
-	queue_work(cx->out_work_queue, &s->out_work_order);
+	schedule_work(&s->out_work_order);
 }
 
 static inline void cx18_stream_put_mdl_fw(struct cx18_stream *s,