Hi AngeloGioacchino,

Thanks for your suggestion.
On Thu, 2021-10-14 at 13:02 +0200, AngeloGioacchino Del Regno wrote:

quoted

Use the dma_set_mask_and_coherent helper to set vdec
DMA bit mask to support 34bits iova space(16GB) that
the mt8192 iommu HW support.

Whole the iova range separate to 0~4G/4G~8G/8G~12G/12G~16G,
regarding which iova range VDEC actually locate, it
depends on the dma-ranges property of vdec dtsi node.

Signed-off-by: Yunfei Dong <yunfei.dong@mediatek.com>
---
  drivers/media/platform/mtk-vcodec/mtk_vcodec_dec_drv.c | 3 +++
  1 file changed, 3 insertions(+)

diff --git a/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec_drv.c 

b/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec_drv.c
index de83e3b821b4..da963cdac96b 100644

--- a/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec_drv.c
+++ b/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec_drv.c

@@ -376,6 +376,9 @@ static int mtk_vcodec_probe(struct

platform_device *pdev)
  		}
  	}
  
+	if (of_get_property(pdev->dev.of_node, "dma-ranges", NULL))
+		dma_set_mask_and_coherent(&pdev->dev,
DMA_BIT_MASK(34));
+

Will fix in patch v8.

This function returns 0 for success, or negative number for failure:
please check
the return value, or this driver may not work correctly in some
corner cases.

Regards,
- Angelo

quoted

  	for (i = 0; i < MTK_VDEC_HW_MAX; i++)
  		mutex_init(&dev->dec_mutex[i]);
  	spin_lock_init(&dev->irqlock);