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Message-Id: <20200608231848.3366970-75-sashal@kernel.org>
Date: Mon, 8 Jun 2020 19:17:08 -0400
From: Sasha Levin <sashal@...nel.org>
To: linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc: Kieran Bingham <kieran.bingham+renesas@...asonboard.com>,
Geert Uytterhoeven <geert+renesas@...der.be>,
Hans Verkuil <hverkuil-cisco@...all.nl>,
Mauro Carvalho Chehab <mchehab+huawei@...nel.org>,
Sasha Levin <sashal@...nel.org>, linux-media@...r.kernel.org,
linux-renesas-soc@...r.kernel.org
Subject: [PATCH AUTOSEL 5.4 075/175] media: platform: fcp: Set appropriate DMA parameters
From: Kieran Bingham <kieran.bingham+renesas@...asonboard.com>
[ Upstream commit dd844fb8e50b12e65bbdc5746c9876c6735500df ]
Enabling CONFIG_DMA_API_DEBUG=y and CONFIG_DMA_API_DEBUG_SG=y will
enable extra validation on DMA operations ensuring that the size
restraints are met.
When using the FCP in conjunction with the VSP1/DU, and display frames,
the size of the DMA operations is larger than the default maximum
segment size reported by the DMA core (64K). With the DMA debug enabled,
this produces a warning such as the following:
"DMA-API: rcar-fcp fea27000.fcp: mapping sg segment longer than device
claims to support [len=3145728] [max=65536]"
We have no specific limitation on the segment size which isn't already
handled by the VSP1/DU which actually handles the DMA allcoations and
buffer management, so define a maximum segment size of up to 4GB (a 32
bit mask).
Reported-by: Geert Uytterhoeven <geert+renesas@...der.be>
Fixes: 7b49235e83b2 ("[media] v4l: Add Renesas R-Car FCP driver")
Signed-off-by: Kieran Bingham <kieran.bingham+renesas@...asonboard.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@...der.be>
Tested-by: Geert Uytterhoeven <geert+renesas@...der.be>
Signed-off-by: Hans Verkuil <hverkuil-cisco@...all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@...nel.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
drivers/media/platform/rcar-fcp.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/media/platform/rcar-fcp.c b/drivers/media/platform/rcar-fcp.c
index 43c78620c9d8..5c6b00737fe7 100644
--- a/drivers/media/platform/rcar-fcp.c
+++ b/drivers/media/platform/rcar-fcp.c
@@ -8,6 +8,7 @@
*/
#include <linux/device.h>
+#include <linux/dma-mapping.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
@@ -21,6 +22,7 @@
struct rcar_fcp_device {
struct list_head list;
struct device *dev;
+ struct device_dma_parameters dma_parms;
};
static LIST_HEAD(fcp_devices);
@@ -136,6 +138,9 @@ static int rcar_fcp_probe(struct platform_device *pdev)
fcp->dev = &pdev->dev;
+ fcp->dev->dma_parms = &fcp->dma_parms;
+ dma_set_max_seg_size(fcp->dev, DMA_BIT_MASK(32));
+
pm_runtime_enable(&pdev->dev);
mutex_lock(&fcp_lock);
--
2.25.1
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