From 1698a7f1511267a0d07a783dd467eab19bf498f3 Mon Sep 17 00:00:00 2001
From: Alexandre Courbot <gnurou@gmail.com>
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 <gnurou@gmail.com>
Reviewed-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
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 121243e5bece1..f626ba5ee3d95 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);
--
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