Re: [PATCH AUTOSEL 4.19 2/4] media: vb2: use lock if wait_prepare/finish are NULL
From: Hans Verkuil
Date: Mon Nov 25 2024 - 02:33:19 EST
Hi Sasha,
This shouldn't be backported. It is not a fix, and it relies on a number of other
changes for this to work anyway, and none of those other changes are backported.
So please drop this patch.
Thank you,
Hans
On 24/11/2024 13:58, Sasha Levin wrote:
> From: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
>
> [ Upstream commit 88785982a19daa765e30ab3a605680202cfaee4e ]
>
> If the wait_prepare or wait_finish callback is set, then call it.
> If it is NULL and the queue lock pointer is not NULL, then just
> unlock/lock that mutex.
>
> This allows simplifying drivers by dropping the wait_prepare and
> wait_finish ops (and eventually the vb2_ops_wait_prepare/finish helpers).
>
> Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
> ---
> drivers/media/common/videobuf2/videobuf2-core.c | 13 ++++++++++---
> 1 file changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
> index 98719aa986bb9..e439831f6df46 100644
> --- a/drivers/media/common/videobuf2/videobuf2-core.c
> +++ b/drivers/media/common/videobuf2/videobuf2-core.c
> @@ -1528,7 +1528,10 @@ static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
> * become ready or for streamoff. Driver's lock is released to
> * allow streamoff or qbuf to be called while waiting.
> */
> - call_void_qop(q, wait_prepare, q);
> + if (q->ops->wait_prepare)
> + call_void_qop(q, wait_prepare, q);
> + else if (q->lock)
> + mutex_unlock(q->lock);
>
> /*
> * All locks have been released, it is safe to sleep now.
> @@ -1538,12 +1541,16 @@ static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
> !list_empty(&q->done_list) || !q->streaming ||
> q->error);
>
> + if (q->ops->wait_finish)
> + call_void_qop(q, wait_finish, q);
> + else if (q->lock)
> + mutex_lock(q->lock);
> +
> + q->waiting_in_dqbuf = 0;
> /*
> * We need to reevaluate both conditions again after reacquiring
> * the locks or return an error if one occurred.
> */
> - call_void_qop(q, wait_finish, q);
> - q->waiting_in_dqbuf = 0;
> if (ret) {
> dprintk(1, "sleep was interrupted\n");
> return ret;