Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
To:     Tomasz Figa <tfiga@chromium.org>,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Hans Verkuil <hverkuil@xs4all.nl>
Cc:     linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
        Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
        Sergey Senozhatsky <senozhatsky@chromium.org>
Subject: [PATCH] media: vb2: always set buffer cache sync hints
Date:   Fri, 27 Nov 2020 18:41:36 +0900
Message-Id: <20201127094136.1051071-1-sergey.senozhatsky@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

We need to always set ->need_cache_sync_on_prepare and
->need_cache_sync_on_finish when we initialize vb2 buffer.

Currently these flags are set/adjusted only in V4L2's
vb2_queue_or_prepare_buf(), which means that for the code
paths that don't use V4L2 vb2 will always tell videobuf2
core to skip ->prepare() and ->finish() cache syncs/flushes.

This is a quick solution that should do the trick. The
proper fix, however, is much more complicated and requires
a rather big videobuf2 refactoring - we need to move cache
sync/flush decision making out of core videobuf2 to the
allocators.

Reported-by: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
---
 drivers/media/common/videobuf2/videobuf2-core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index 5499013cf82e..14a26888a892 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -414,6 +414,8 @@ static int __vb2_queue_alloc(struct vb2_queue *q, enum vb2_memory memory,
 		vb->index = q->num_buffers + buffer;
 		vb->type = q->type;
 		vb->memory = memory;
+		vb->need_cache_sync_on_prepare = 1;
+		vb->need_cache_sync_on_finish = 1;
 		for (plane = 0; plane < num_planes; ++plane) {
 			vb->planes[plane].length = plane_sizes[plane];
 			vb->planes[plane].min_length = plane_sizes[plane];
-- 
2.29.2