linux-kernel - [RFC][PATCHv2 07/12] videobuf2: do not sync caches when we are allowed not to

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Date:   Tue,  4 Feb 2020 11:56:36 +0900
From:   Sergey Senozhatsky <senozhatsky@...omium.org>
To:     Hans Verkuil <hans.verkuil@...co.com>,
        Tomasz Figa <tfiga@...omium.org>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Kyungmin Park <kyungmin.park@...sung.com>,
        Marek Szyprowski <m.szyprowski@...sung.com>
Cc:     Sakari Ailus <sakari.ailus@....fi>,
        Laurent Pinchart <laurent.pinchart@...asonboard.com>,
        Pawel Osciak <posciak@...omium.org>,
        linux-media@...r.kernel.org, linux-kernel@...r.kernel.org,
        Sergey Senozhatsky <senozhatsky@...omium.org>
Subject: [RFC][PATCHv2 07/12] videobuf2: do not sync caches when we are allowed not to

Skip ->prepare() or/and ->finish() cache synchronisation if
user-space requested us to do so (or when queue dma direction
permits us to skip cache syncs).

Change-Id: I37c89d666542ed8d536eac329953d921bb1c94b6
Signed-off-by: Sergey Senozhatsky <senozhatsky@...omium.org>
---
 drivers/media/common/videobuf2/videobuf2-core.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index 46be9c790ff6..c3637ca0c65b 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -304,8 +304,11 @@ static void __vb2_buf_mem_prepare(struct vb2_buffer *vb)
 {
 	unsigned int plane;
 
-	for (plane = 0; plane < vb->num_planes; ++plane)
-		call_void_memop(vb, prepare, vb->planes[plane].mem_priv);
+	if (vb->need_cache_sync_on_prepare) {
+		for (plane = 0; plane < vb->num_planes; ++plane)
+			call_void_memop(vb, prepare,
+					vb->planes[plane].mem_priv);
+	}
 	vb->synced = 1;
 }
 
@@ -317,8 +320,11 @@ static void __vb2_buf_mem_finish(struct vb2_buffer *vb)
 {
 	unsigned int plane;
 
-	for (plane = 0; plane < vb->num_planes; ++plane)
-		call_void_memop(vb, finish, vb->planes[plane].mem_priv);
+	if (vb->need_cache_sync_on_finish) {
+		for (plane = 0; plane < vb->num_planes; ++plane)
+			call_void_memop(vb, finish,
+					vb->planes[plane].mem_priv);
+	}
 	vb->synced = 0;
 }
 
-- 
2.25.0.341.g760bfbb309-goog