Re: [PATCH 11/32] v4l/cx18: update workqueue usage

[Andy Walls <awalls@md.metrocast.net>]

On Mon, 2011-01-03 at 14:49 +0100, Tejun Heo wrote:
> 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>
> Cc: Andy Walls <awalls@md.metrocast.net>
> Cc: linux-media@vger.kernel.org
> ---
> Only compile tested.  Please feel free to take it into the subsystem
> tree or simply ack - I'll route it through the wq tree.

Reviewed-by: Andy Walls <awalls@md.metrocast.net>
Acked-by: Andy Walls <awalls@md.metrocast.net>

Sorry it took so long for me to review.
Please route via your wq tree for the cx18 driver.

Thanks,
Andy

> Thanks.
> 
>  drivers/media/video/cx18/cx18-driver.c  |   24 ++----------------------
>  drivers/media/video/cx18/cx18-driver.h  |    3 ---
>  drivers/media/video/cx18/cx18-streams.h |    3 +--
>  3 files changed, 3 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/media/video/cx18/cx18-driver.c b/drivers/media/video/cx18/cx18-driver.c
> index df60f27..41c0822 100644
> --- a/drivers/media/video/cx18/cx18-driver.c
> +++ b/drivers/media/video/cx18/cx18-driver.c
> @@ -656,7 +656,7 @@ 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;
> @@ -664,18 +664,6 @@ 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;
> @@ -702,15 +690,9 @@ 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);
>  
> @@ -1094,7 +1076,6 @@ 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;
> @@ -1244,7 +1225,6 @@ 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);
>  
> diff --git a/drivers/media/video/cx18/cx18-driver.h b/drivers/media/video/cx18/cx18-driver.h
> index 77be58c..f7f71d1 100644
> --- a/drivers/media/video/cx18/cx18-driver.h
> +++ b/drivers/media/video/cx18/cx18-driver.h
> @@ -614,9 +614,6 @@ 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];
> diff --git a/drivers/media/video/cx18/cx18-streams.h b/drivers/media/video/cx18/cx18-streams.h
> index 77412be..5837ffb 100644
> --- a/drivers/media/video/cx18/cx18-streams.h
> +++ b/drivers/media/video/cx18/cx18-streams.h
> @@ -41,8 +41,7 @@ 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,