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Date: Thu, 27 Aug 2020 21:49:46 +0900 From: Alexandre Courbot <gnurou@...il.com> To: Mauro Carvalho Chehab <mchehab@...nel.org>, Hans Verkuil <hverkuil-cisco@...all.nl>, Nicolas Dufresne <nicolas.dufresne@...labora.com>, Ezequiel Garcia <ezequiel@...guardiasur.com.ar> Cc: linux-media@...r.kernel.org, linux-kernel@...r.kernel.org, Alexandre Courbot <gnurou@...il.com> Subject: [PATCH v2 2/2] media: v4l2-mem2mem: simplify poll logic Factorize redundant checks into a single code block, remove unneeded checks (a buffer in done_list is necessarily in the DONE or ERROR state), and we end up with a much simpler version of this function. Signed-off-by: Alexandre Courbot <gnurou@...il.com> --- drivers/media/v4l2-core/v4l2-mem2mem.c | 26 +++++--------------------- 1 file changed, 5 insertions(+), 21 deletions(-) diff --git a/drivers/media/v4l2-core/v4l2-mem2mem.c b/drivers/media/v4l2-core/v4l2-mem2mem.c index fe90c3c0e4128..af8138c5d7ced 100644 --- a/drivers/media/v4l2-core/v4l2-mem2mem.c +++ b/drivers/media/v4l2-core/v4l2-mem2mem.c @@ -841,7 +841,6 @@ static __poll_t v4l2_m2m_poll_for_data(struct file *file, struct poll_table_struct *wait) { struct vb2_queue *src_q, *dst_q; - struct vb2_buffer *src_vb = NULL, *dst_vb = NULL; __poll_t rc = 0; unsigned long flags; @@ -862,32 +861,17 @@ static __poll_t v4l2_m2m_poll_for_data(struct file *file, list_empty(&dst_q->queued_list))) return EPOLLERR; - spin_lock_irqsave(&dst_q->done_lock, flags); - if (list_empty(&dst_q->done_list)) { - /* - * If the last buffer was dequeued from the capture queue, - * return immediately. DQBUF will return -EPIPE. - */ - if (dst_q->last_buffer_dequeued) - rc |= EPOLLIN | EPOLLRDNORM; - } - spin_unlock_irqrestore(&dst_q->done_lock, flags); - spin_lock_irqsave(&src_q->done_lock, flags); if (!list_empty(&src_q->done_list)) - src_vb = list_first_entry(&src_q->done_list, struct vb2_buffer, - done_entry); - if (src_vb && (src_vb->state == VB2_BUF_STATE_DONE - || src_vb->state == VB2_BUF_STATE_ERROR)) rc |= EPOLLOUT | EPOLLWRNORM; spin_unlock_irqrestore(&src_q->done_lock, flags); spin_lock_irqsave(&dst_q->done_lock, flags); - if (!list_empty(&dst_q->done_list)) - dst_vb = list_first_entry(&dst_q->done_list, struct vb2_buffer, - done_entry); - if (dst_vb && (dst_vb->state == VB2_BUF_STATE_DONE - || dst_vb->state == VB2_BUF_STATE_ERROR)) + /* + * If the last buffer was dequeued from the capture queue, signal + * userspace. DQBUF(CAPTURE) will return -EPIPE. + */ + if (!list_empty(&dst_q->done_list) || dst_q->last_buffer_dequeued) rc |= EPOLLIN | EPOLLRDNORM; spin_unlock_irqrestore(&dst_q->done_lock, flags); -- 2.28.0
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