Hi Raimonds, Jurgen,
Can you both test this patch? It should (I hope) solve the problems you
both had with the cx23885 driver.
This patch fixes a race condition in the vb2_thread that occurs when
the thread is stopped. The crucial fix is calling kthread_stop much
earlier in vb2_thread_stop(). But I also made the vb2_thread more
robust.
Regards,
Hans
Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index d09a891..bc08a82 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -3146,27 +3146,26 @@ static int vb2_thread(void *data)
prequeue--;
} else {
call_void_qop(q, wait_finish, q);
- ret = vb2_internal_dqbuf(q, &fileio->b, 0);
+ if (!threadio->stop)
+ ret = vb2_internal_dqbuf(q, &fileio->b, 0);
call_void_qop(q, wait_prepare, q);
dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
}
- if (threadio->stop)
- break;
- if (ret)
+ if (ret || threadio->stop)
break;
try_to_freeze();
vb = q->bufs[fileio->b.index];
if (!(fileio->b.flags & V4L2_BUF_FLAG_ERROR))
- ret = threadio->fnc(vb, threadio->priv);
- if (ret)
- break;
+ if (threadio->fnc(vb, threadio->priv))
+ break;
call_void_qop(q, wait_finish, q);
if (set_timestamp)
v4l2_get_timestamp(&fileio->b.timestamp);
- ret = vb2_internal_qbuf(q, &fileio->b);
+ if (!threadio->stop)
+ ret = vb2_internal_qbuf(q, &fileio->b);
call_void_qop(q, wait_prepare, q);
- if (ret)
+ if (ret || threadio->stop)
break;
}
@@ -3235,11 +3234,11 @@ int vb2_thread_stop(struct vb2_queue *q)
threadio->stop = true;
vb2_internal_streamoff(q, q->type);
call_void_qop(q, wait_prepare, q);
+ err = kthread_stop(threadio->thread);
q->fileio = NULL;
fileio->req.count = 0;
vb2_reqbufs(q, &fileio->req);
kfree(fileio);
- err = kthread_stop(threadio->thread);
threadio->thread = NULL;
kfree(threadio);
q->fileio = NULL;
--
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