From: Hans Verkuil <hans.verk...@cisco.com>

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.verk...@cisco.com>
---
 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 462099a141e4..6f87ef025ff1 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);
 
-- 
2.18.0

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