[media] pvrusb2: Remove deprecated create_singlethread_workqueue

The workqueue "workqueue" is involved in polling the pvrusb2 hardware
(pvr2_hdw).

It has a single work item(&hdw->workpoll) 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 pvr2_hdw_destroy to ensure that there are no
pending tasks while disconnecting the driver.

Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

diff --git a/drivers/media/usb/pvrusb2/pvrusb2-hdw-internal.h b/drivers/media/usb/pvrusb2/pvrusb2-hdw-internal.h
index 60141b16d731059b905bc1690b3c6a1b8bd5d1d3..23473a21319cd4275a663b77e5fef0850602feb2 100644 (file)
--- a/drivers/media/usb/pvrusb2/pvrusb2-hdw-internal.h
+++ b/drivers/media/usb/pvrusb2/pvrusb2-hdw-internal.h
@@ -170,7 +170,6 @@ struct pvr2_hdw {
        const struct pvr2_device_desc *hdw_desc;
 
        /* Kernel worker thread handling */
-       struct workqueue_struct *workqueue;
        struct work_struct workpoll;     /* Update driver state */
 
        /* Video spigot */

diff --git a/drivers/media/usb/pvrusb2/pvrusb2-hdw.c b/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
index fe20fe4f2330d8c05c1006bc33edc39b2ac07738..1eb4f7ba2967d0777b71b30c7765b07168a0b27b 100644 (file)
--- a/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
+++ b/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
@@ -2624,7 +2624,6 @@ struct pvr2_hdw *pvr2_hdw_create(struct usb_interface *intf,
        if (cnt1 >= sizeof(hdw->name)) cnt1 = sizeof(hdw->name)-1;
        hdw->name[cnt1] = 0;
 
-       hdw->workqueue = create_singlethread_workqueue(hdw->name);
        INIT_WORK(&hdw->workpoll,pvr2_hdw_worker_poll);
 
        pvr2_trace(PVR2_TRACE_INIT,"Driver unit number is %d, name is %s",
@@ -2651,11 +2650,7 @@ struct pvr2_hdw *pvr2_hdw_create(struct usb_interface *intf,
                del_timer_sync(&hdw->decoder_stabilization_timer);
                del_timer_sync(&hdw->encoder_run_timer);
                del_timer_sync(&hdw->encoder_wait_timer);
-               if (hdw->workqueue) {
-                       flush_workqueue(hdw->workqueue);
-                       destroy_workqueue(hdw->workqueue);
-                       hdw->workqueue = NULL;
-               }
+               flush_work(&hdw->workpoll);
                usb_free_urb(hdw->ctl_read_urb);
                usb_free_urb(hdw->ctl_write_urb);
                kfree(hdw->ctl_read_buffer);
@@ -2712,11 +2707,7 @@ void pvr2_hdw_destroy(struct pvr2_hdw *hdw)
 {
        if (!hdw) return;
        pvr2_trace(PVR2_TRACE_INIT,"pvr2_hdw_destroy: hdw=%p",hdw);
-       if (hdw->workqueue) {
-               flush_workqueue(hdw->workqueue);
-               destroy_workqueue(hdw->workqueue);
-               hdw->workqueue = NULL;
-       }
+       flush_work(&hdw->workpoll);
        del_timer_sync(&hdw->quiescent_timer);
        del_timer_sync(&hdw->decoder_stabilization_timer);
        del_timer_sync(&hdw->encoder_run_timer);
@@ -4443,7 +4434,7 @@ static void pvr2_hdw_quiescent_timeout(unsigned long data)
        hdw->state_decoder_quiescent = !0;
        trace_stbit("state_decoder_quiescent",hdw->state_decoder_quiescent);
        hdw->state_stale = !0;
-       queue_work(hdw->workqueue,&hdw->workpoll);
+       schedule_work(&hdw->workpoll);
 }
 
 
@@ -4454,7 +4445,7 @@ static void pvr2_hdw_decoder_stabilization_timeout(unsigned long data)
        hdw->state_decoder_ready = !0;
        trace_stbit("state_decoder_ready", hdw->state_decoder_ready);
        hdw->state_stale = !0;
-       queue_work(hdw->workqueue, &hdw->workpoll);
+       schedule_work(&hdw->workpoll);
 }
 
 
@@ -4465,7 +4456,7 @@ static void pvr2_hdw_encoder_wait_timeout(unsigned long data)
        hdw->state_encoder_waitok = !0;
        trace_stbit("state_encoder_waitok",hdw->state_encoder_waitok);
        hdw->state_stale = !0;
-       queue_work(hdw->workqueue,&hdw->workpoll);
+       schedule_work(&hdw->workpoll);
 }
 
 
@@ -4477,7 +4468,7 @@ static void pvr2_hdw_encoder_run_timeout(unsigned long data)
                hdw->state_encoder_runok = !0;
                trace_stbit("state_encoder_runok",hdw->state_encoder_runok);
                hdw->state_stale = !0;
-               queue_work(hdw->workqueue,&hdw->workpoll);
+               schedule_work(&hdw->workpoll);
        }
 }
 
@@ -4991,7 +4982,7 @@ static void pvr2_hdw_state_sched(struct pvr2_hdw *hdw)
        if (hdw->state_stale) return;
        hdw->state_stale = !0;
        trace_stbit("state_stale",hdw->state_stale);
-       queue_work(hdw->workqueue,&hdw->workpoll);
+       schedule_work(&hdw->workpoll);
 }