From 53eebd84c3ac2a81da94535594dba6ff637311dd Mon Sep 17 00:00:00 2001 From: Bhaktipriya Shridhar Date: Sat, 16 Jul 2016 05:55:56 -0300 Subject: [PATCH] [media] gspca: finepix: Remove deprecated create_singlethread_workqueue The workqueue "work_thread" is involved in streaming the camera data. It has a single work item(&dev->work_struct) 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 flushed in sd_stop0() to ensure that there are no pending tasks while disconnecting the driver. Signed-off-by: Bhaktipriya Shridhar Acked-by: Tejun Heo Acked-by: Frank Zago Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/usb/gspca/finepix.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/drivers/media/usb/gspca/finepix.c b/drivers/media/usb/gspca/finepix.c index 52bdb569760b..ae9a55d7bbbb 100644 --- a/drivers/media/usb/gspca/finepix.c +++ b/drivers/media/usb/gspca/finepix.c @@ -41,7 +41,6 @@ struct usb_fpix { struct gspca_dev gspca_dev; /* !! must be the first item */ struct work_struct work_struct; - struct workqueue_struct *work_thread; }; /* Delay after which claim the next frame. If the delay is too small, @@ -226,9 +225,7 @@ static int sd_start(struct gspca_dev *gspca_dev) /* Again, reset bulk in endpoint */ usb_clear_halt(gspca_dev->dev, gspca_dev->urb[0]->pipe); - /* Start the workqueue function to do the streaming */ - dev->work_thread = create_singlethread_workqueue(MODULE_NAME); - queue_work(dev->work_thread, &dev->work_struct); + schedule_work(&dev->work_struct); return 0; } @@ -241,9 +238,8 @@ static void sd_stop0(struct gspca_dev *gspca_dev) /* wait for the work queue to terminate */ mutex_unlock(&gspca_dev->usb_lock); - destroy_workqueue(dev->work_thread); + flush_work(&dev->work_struct); mutex_lock(&gspca_dev->usb_lock); - dev->work_thread = NULL; } /* Table of supported USB devices */ -- 2.30.2