From: Alexandre Courbot <gnurou@gmail.com>
To: Mauro Carvalho Chehab <mchehab@kernel.org>,
Hans Verkuil <hverkuil-cisco@xs4all.nl>,
Nicolas Dufresne <nicolas.dufresne@collabora.com>
Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
Alexandre Courbot <gnurou@gmail.com>
Subject: [PATCH 2/2] media: v4l2-mem2mem: simplify poll logic a bit
Date: Tue, 25 Aug 2020 23:55:56 +0900 [thread overview]
Message-ID: <20200825145556.637323-3-gnurou@gmail.com> (raw)
In-Reply-To: <20200825145556.637323-1-gnurou@gmail.com>
Factorize redundant checks into a single code block, remove the early
return, and declare variables in their innermost block. Hopefully this
makes this code a little bit easier to follow.
Signed-off-by: Alexandre Courbot <gnurou@gmail.com>
---
drivers/media/v4l2-core/v4l2-mem2mem.c | 35 +++++++++++---------------
1 file changed, 15 insertions(+), 20 deletions(-)
diff --git a/drivers/media/v4l2-core/v4l2-mem2mem.c b/drivers/media/v4l2-core/v4l2-mem2mem.c
index 0d0192119af20..aeac9707123d0 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;
@@ -863,33 +862,29 @@ static __poll_t v4l2_m2m_poll_for_data(struct file *file,
return EPOLLERR;
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;
+ if (!list_empty(&src_q->done_list)) {
+ struct vb2_buffer *src_vb = list_first_entry(
+ &src_q->done_list, struct vb2_buffer, done_entry);
+ if (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)) {
+ if (!list_empty(&dst_q->done_list)) {
+ struct vb2_buffer *dst_vb = list_first_entry(
+ &dst_q->done_list, struct vb2_buffer, done_entry);
+ if (dst_vb->state == VB2_BUF_STATE_DONE ||
+ dst_vb->state == VB2_BUF_STATE_ERROR)
+ rc |= EPOLLIN | EPOLLRDNORM;
+ } else if (dst_q->last_buffer_dequeued) {
/*
* If the last buffer was dequeued from the capture queue,
* return immediately. DQBUF will return -EPIPE.
*/
- if (dst_q->last_buffer_dequeued) {
- spin_unlock_irqrestore(&dst_q->done_lock, flags);
- rc |= EPOLLIN | EPOLLRDNORM;
- return rc;
- }
- }
-
- 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))
rc |= EPOLLIN | EPOLLRDNORM;
+ }
spin_unlock_irqrestore(&dst_q->done_lock, flags);
return rc;
--
2.28.0
next prev parent reply other threads:[~2020-08-25 14:57 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-25 14:55 [PATCH 0/2] media: v4l2-mem2mem: fix poll() bug Alexandre Courbot
2020-08-25 14:55 ` [PATCH 1/2] media: v4l2-mem2mem: consider OUTPUT queue first when polling Alexandre Courbot
2020-08-26 4:07 ` Ezequiel Garcia
2020-08-26 11:21 ` Alexandre Courbot
2020-08-25 14:55 ` Alexandre Courbot [this message]
2020-08-26 4:15 ` [PATCH 2/2] media: v4l2-mem2mem: simplify poll logic a bit Ezequiel Garcia
2020-08-26 11:19 ` Alexandre Courbot
2020-08-26 14:32 ` Ezequiel Garcia
2020-08-26 15:23 ` Hans Verkuil
2020-08-26 12:46 ` Hans Verkuil
2020-08-25 22:10 ` [PATCH 0/2] media: v4l2-mem2mem: fix poll() bug Ezequiel Garcia
2020-08-26 11:25 ` Alexandre Courbot
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