[4.2.y-ckt stable] Patch "[media] media: vb2 dma-contig: Fully cache synchronise buffers in prepare and finish" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    [media] media: vb2 dma-contig: Fully cache synchronise buffers in prepare and finish

to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-4.2.y-queue

This patch is scheduled to be released in version 4.2.8-ckt1.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 4.2.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 9dbe60844c15ea0c5ac706828eafec8ffd247457 Mon Sep 17 00:00:00 2001
From: Tiffany Lin <tiffany.lin at mediatek.com>
Date: Thu, 24 Sep 2015 06:02:36 -0300
Subject: [media] media: vb2 dma-contig: Fully cache synchronise buffers in
 prepare and finish

commit d9a985883fa32453d099d6293188c11d75cef1fa upstream.

In videobuf2 dma-contig memory type the prepare and finish ops, instead of
passing the number of entries in the original scatterlist as the "nents"
parameter to dma_sync_sg_for_device() and dma_sync_sg_for_cpu(), the value
returned by dma_map_sg() was used. Albeit this has been suggested in
comments of some implementations (which have since been corrected), this
is wrong.

Fixes: 199d101efdba ("v4l: vb2-dma-contig: add prepare/finish to dma-contig allocator")

Signed-off-by: Tiffany Lin <tiffany.lin at mediatek.com>
Signed-off-by: Sakari Ailus <sakari.ailus at linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab at osg.samsung.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/media/v4l2-core/videobuf2-dma-contig.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c
index 94c1e64..f8afbd0 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c
@@ -120,7 +120,8 @@ static void vb2_dc_prepare(void *buf_priv)
 	if (!sgt || buf->db_attach)
 		return;

-	dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
+	dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->orig_nents,
+			       buf->dma_dir);
 }

 static void vb2_dc_finish(void *buf_priv)
@@ -132,7 +133,7 @@ static void vb2_dc_finish(void *buf_priv)
 	if (!sgt || buf->db_attach)
 		return;

-	dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
+	dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir);
 }

 /*********************************************/
--
1.9.1