From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932079AbcGBKoA (ORCPT ); Sat, 2 Jul 2016 06:44:00 -0400 Received: from mail-pa0-f68.google.com ([209.85.220.68]:35048 "EHLO mail-pa0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750804AbcGBKn7 (ORCPT ); Sat, 2 Jul 2016 06:43:59 -0400 Date: Sat, 2 Jul 2016 16:13:55 +0530 From: Bhaktipriya Shridhar To: Hans Verkuil , Mauro Carvalho Chehab Cc: Tejun Heo , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] [media] adv7604: Remove deprecated create_singlethread_workqueue Message-ID: <20160702104355.GA2100@Karyakshetra> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The workqueue "work_queues" enables hotplugging. It has a single work item(&state->delayed_work_enable_hotplug) and hence doesn't require ordering. Also, it is not being used on a memory reclaim path. Hence, the singlethreaded workqueue has been replaced with the use of system_wq. System workqueues have been able to handle high level of concurrency for a long time now and hence it's not required to have a singlethreaded workqueue just to gain concurrency. Unlike a dedicated per-cpu workqueue created with create_singlethread_workqueue(), system_wq allows multiple work items to overlap executions even on the same CPU; however, a per-cpu workqueue doesn't have any CPU locality or global ordering guarantee unless the target CPU is explicitly specified and thus the increase of local concurrency shouldn't make any difference. Work item has been sync cancelled in adv76xx_remove() to ensure that there are no pending tasks while disconnecting the driver. Signed-off-by: Bhaktipriya Shridhar --- drivers/media/i2c/adv7604.c | 14 +------------- 1 file changed, 1 insertion(+), 13 deletions(-) diff --git a/drivers/media/i2c/adv7604.c b/drivers/media/i2c/adv7604.c index beb2841..010f24c 100644 --- a/drivers/media/i2c/adv7604.c +++ b/drivers/media/i2c/adv7604.c @@ -184,7 +184,6 @@ struct adv76xx_state { u16 spa_port_a[2]; struct v4l2_fract aspect_ratio; u32 rgb_quantization_range; - struct workqueue_struct *work_queues; struct delayed_work delayed_work_enable_hotplug; bool restart_stdi_once; @@ -2130,8 +2129,7 @@ static int adv76xx_set_edid(struct v4l2_subdev *sd, struct v4l2_edid *edid) } /* enable hotplug after 100 ms */ - queue_delayed_work(state->work_queues, - &state->delayed_work_enable_hotplug, HZ / 10); + schedule_delayed_work(&state->delayed_work_enable_hotplug, HZ / 10); return 0; } @@ -3182,14 +3180,6 @@ static int adv76xx_probe(struct i2c_client *client, } } - /* work queues */ - state->work_queues = create_singlethread_workqueue(client->name); - if (!state->work_queues) { - v4l2_err(sd, "Could not create work queue\n"); - err = -ENOMEM; - goto err_i2c; - } - INIT_DELAYED_WORK(&state->delayed_work_enable_hotplug, adv76xx_delayed_work_enable_hotplug); @@ -3225,7 +3215,6 @@ err_entity: media_entity_cleanup(&sd->entity); err_work_queues: cancel_delayed_work(&state->delayed_work_enable_hotplug); - destroy_workqueue(state->work_queues); err_i2c: adv76xx_unregister_clients(state); err_hdl: @@ -3241,7 +3230,6 @@ static int adv76xx_remove(struct i2c_client *client) struct adv76xx_state *state = to_state(sd); cancel_delayed_work(&state->delayed_work_enable_hotplug); - destroy_workqueue(state->work_queues); v4l2_async_unregister_subdev(sd); media_entity_cleanup(&sd->entity); adv76xx_unregister_clients(to_state(sd)); -- 2.1.4