From 1698a7f1511267a0d07a783dd467eab19bf498f3 Mon Sep 17 00:00:00 2001 From: Alexandre Courbot Date: Thu, 27 Aug 2020 14:49:46 +0200 Subject: [PATCH] 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 Reviewed-by: Ezequiel Garcia Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- 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 121243e5bece..f626ba5ee3d9 100644 --- a/drivers/media/v4l2-core/v4l2-mem2mem.c +++ b/drivers/media/v4l2-core/v4l2-mem2mem.c @@ -882,7 +882,6 @@ 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; @@ -903,32 +902,17 @@ 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);