Re: [PATCH v2] fsldma: add support to 36-bit physical address

From: Kumar Gala
Date: Thu Nov 11 2010 - 06:56:49 EST



On Nov 11, 2010, at 6:16 AM, Li Yang wrote:

> Expand the dma_mask of fsldma device to 36-bit, indicating that the
> DMA engine can deal with 36-bit physical address and does not need
> the SWIOTLB to create bounce buffer for it when doing dma_map_*().
>
> Signed-off-by: Li Yang <leoli@xxxxxxxxxxxxx>
> ---
> Add more detailed commit message
>
> drivers/dma/fsldma.c | 4 +++-
> 1 files changed, 3 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c
> index cea08be..8c79b37 100644
> --- a/drivers/dma/fsldma.c
> +++ b/drivers/dma/fsldma.c
> @@ -1,7 +1,7 @@
> /*
> * Freescale MPC85xx, MPC83xx DMA Engine support
> *
> - * Copyright (C) 2007 Freescale Semiconductor, Inc. All rights reserved.
> + * Copyright (C) 2007-2010 Freescale Semiconductor, Inc. All rights reserved.
> *
> * Author:
> * Zhang Wei <wei.zhang@xxxxxxxxxxxxx>, Jul 2007
> @@ -1338,6 +1338,8 @@ static int __devinit fsldma_of_probe(struct platform_device *op,
> fdev->common.device_control = fsl_dma_device_control;
> fdev->common.dev = &op->dev;
>
> + dma_set_mask(&(op->dev), DMA_BIT_MASK(36));
> +

Is there any reason we shouldn't set DMA_BIT_MASK(64) since the DMA block programming model allows the address to be 64-bits?

> dev_set_drvdata(&op->dev, fdev);
>
> /*
> --
> 1.6.6-rc1.GIT
>

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