[media] s2255drv: fix spinlock issue

qlock spinlock controls access to buf_list and sequence.
qlock spinlock should not be locked during a copy to video buffers, an
operation that may sleep.

Signed-off-by: Dean Anderson <linux-dev@sensoray.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

diff --git a/drivers/media/usb/s2255/s2255drv.c b/drivers/media/usb/s2255/s2255drv.c
index ccc00099b26144e4bd1c5b99cbfccbf266a50ad7..a56a05b0c4e1e686ef45bbe6127452e60bdc240f 100644 (file)
--- a/drivers/media/usb/s2255/s2255drv.c
+++ b/drivers/media/usb/s2255/s2255drv.c
@@ -558,27 +558,30 @@ static void s2255_fwchunk_complete(struct urb *urb)
 
 }
 
-static int s2255_got_frame(struct s2255_vc *vc, int jpgsize)
+static void s2255_got_frame(struct s2255_vc *vc, int jpgsize)
 {
        struct s2255_buffer *buf;
        struct s2255_dev *dev = to_s2255_dev(vc->vdev.v4l2_dev);
        unsigned long flags = 0;
-       int rc = 0;
+
        spin_lock_irqsave(&vc->qlock, flags);
        if (list_empty(&vc->buf_list)) {
                dprintk(dev, 1, "No active queue to serve\n");
-               rc = -1;
-               goto unlock;
+               spin_unlock_irqrestore(&vc->qlock, flags);
+               return;
        }
        buf = list_entry(vc->buf_list.next,
                         struct s2255_buffer, list);
        list_del(&buf->list);
        v4l2_get_timestamp(&buf->vb.v4l2_buf.timestamp);
+       buf->vb.v4l2_buf.field = vc->field;
+       buf->vb.v4l2_buf.sequence = vc->frame_count;
+       spin_unlock_irqrestore(&vc->qlock, flags);
+
        s2255_fillbuff(vc, buf, jpgsize);
+       /* tell v4l buffer was filled */
+       vb2_buffer_done(&buf->vb, VB2_BUF_STATE_DONE);
        dprintk(dev, 2, "%s: [buf] [%p]\n", __func__, buf);
-unlock:
-       spin_unlock_irqrestore(&vc->qlock, flags);
-       return rc;
 }
 
 static const struct s2255_fmt *format_by_fourcc(int fourcc)
@@ -649,11 +652,6 @@ static void s2255_fillbuff(struct s2255_vc *vc,
        }
        dprintk(dev, 2, "s2255fill at : Buffer 0x%08lx size= %d\n",
                (unsigned long)vbuf, pos);
-       /* tell v4l buffer was filled */
-       buf->vb.v4l2_buf.field = vc->field;
-       buf->vb.v4l2_buf.sequence = vc->frame_count;
-       v4l2_get_timestamp(&buf->vb.v4l2_buf.timestamp);
-       vb2_buffer_done(&buf->vb, VB2_BUF_STATE_DONE);
 }