From dd844fb8e50b12e65bbdc5746c9876c6735500df Mon Sep 17 00:00:00 2001 From: Kieran Bingham Date: Tue, 7 Apr 2020 17:44:17 +0200 Subject: [PATCH] media: platform: fcp: Set appropriate DMA parameters 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 Fixes: 7b49235e83b2 ("[media] v4l: Add Renesas R-Car FCP driver") Signed-off-by: Kieran Bingham Reviewed-by: Geert Uytterhoeven Tested-by: Geert Uytterhoeven Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- 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 43c7862..5c6b007 100644 --- a/drivers/media/platform/rcar-fcp.c +++ b/drivers/media/platform/rcar-fcp.c @@ -8,6 +8,7 @@ */ #include +#include #include #include #include @@ -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); -- 2.7.4