[PATCH 4.19 060/190] media: vim2m: use workqueue

Greg Kroah-Hartman
2019-09-13T13:13:49Z

[ Upstream commit 144bd0ee304c7d0690eec285aee93019d3f30fc8 ]

v4l2_ctrl uses mutexes, so we can't setup a ctrl_handler in
interrupt context. Switch to a workqueue instead and drop the timer.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/media/platform/vim2m.c | 25 ++++++++++---------------
1 file changed, 10 insertions(+), 15 deletions(-)

diff --git a/drivers/media/platform/vim2m.c b/drivers/media/platform/vim2m.c
index 462099a141e4a..6f87ef025ff19 100644
--- a/drivers/media/platform/vim2m.c
+++ b/drivers/media/platform/vim2m.c
@@ -3,7 +3,8 @@
*
* This is a virtual device driver for testing mem-to-mem videobuf framework.
* It simulates a device that uses memory buffers for both source and
- * destination, processes the data and issues an "irq" (simulated by a timer).
+ * destination, processes the data and issues an "irq" (simulated by a delayed
+ * workqueue).
* The device is capable of multi-instance, multi-buffer-per-transaction
* operation (via the mem2mem framework).
*
@@ -19,7 +20,6 @@
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/fs.h>
-#include <linux/timer.h>
#include <linux/sched.h>
#include <linux/slab.h>

@@ -148,7 +148,7 @@ struct vim2m_dev {
struct mutex dev_mutex;
spinlock_t irqlock;

- struct timer_list timer;
+ struct delayed_work work_run;

struct v4l2_m2m_dev *m2m_dev;
};
@@ -336,12 +336,6 @@ static int device_process(struct vim2m_ctx *ctx,
return 0;
}

-static void schedule_irq(struct vim2m_dev *dev, int msec_timeout)
-{
- dprintk(dev, "Scheduling a simulated irq\n");
- mod_timer(&dev->timer, jiffies + msecs_to_jiffies(msec_timeout));
-}
-
/*
* mem2mem callbacks
*/
@@ -387,13 +381,14 @@ static void device_run(void *priv)

device_process(ctx, src_buf, dst_buf);

- /* Run a timer, which simulates a hardware irq */
- schedule_irq(dev, ctx->transtime);
+ /* Run delayed work, which simulates a hardware irq */
+ schedule_delayed_work(&dev->work_run, msecs_to_jiffies(ctx->transtime));
}

-static void device_isr(struct timer_list *t)
+static void device_work(struct work_struct *w)
{
- struct vim2m_dev *vim2m_dev = from_timer(vim2m_dev, t, timer);
+ struct vim2m_dev *vim2m_dev =
+ container_of(w, struct vim2m_dev, work_run.work);
struct vim2m_ctx *curr_ctx;
struct vb2_v4l2_buffer *src_vb, *dst_vb;
unsigned long flags;
@@ -805,6 +800,7 @@ static void vim2m_stop_streaming(struct vb2_queue *q)
struct vb2_v4l2_buffer *vbuf;
unsigned long flags;

+ flush_scheduled_work();
for (;;) {
if (V4L2_TYPE_IS_OUTPUT(q->type))
vbuf = v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx);
@@ -1015,6 +1011,7 @@ static int vim2m_probe(struct platform_device *pdev)
vfd = &dev->vfd;
vfd->lock = &dev->dev_mutex;
vfd->v4l2_dev = &dev->v4l2_dev;
+ INIT_DELAYED_WORK(&dev->work_run, device_work);

ret = video_register_device(vfd, VFL_TYPE_GRABBER, 0);
if (ret) {
@@ -1026,7 +1023,6 @@ static int vim2m_probe(struct platform_device *pdev)
v4l2_info(&dev->v4l2_dev,
"Device registered as /dev/video%d\n", vfd->num);

- timer_setup(&dev->timer, device_isr, 0);
platform_set_drvdata(pdev, dev);

dev->m2m_dev = v4l2_m2m_init(&m2m_ops);
@@ -1083,7 +1079,6 @@ static int vim2m_remove(struct platform_device *pdev)
media_device_cleanup(&dev->mdev);
#endif
v4l2_m2m_release(dev->m2m_dev);
- del_timer_sync(&dev->timer);
video_unregister_device(&dev->vfd);
v4l2_device_unregister(&dev->v4l2_dev);

--
2.20.1