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Subject: Re: [RFC PATCH 1/2] dma-buf: Fix pin callback comment
To:     Gal Pressman <galpress@amazon.com>,
        Sumit Semwal <sumit.semwal@linaro.org>,
        Doug Ledford <dledford@redhat.com>,
        Jason Gunthorpe <jgg@ziepe.ca>
Cc:     linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org,
        Oded Gabbay <ogabbay@habana.ai>,
        Tomer Tayar <ttayar@habana.ai>,
        Yossi Leybovich <sleybo@amazon.com>,
        Alexander Matushevsky <matua@amazon.com>,
        Leon Romanovsky <leonro@nvidia.com>,
        Jianxin Xiong <jianxin.xiong@intel.com>,
        Firas Jahjah <firasj@amazon.com>
References: <20211007104301.76693-1-galpress@amazon.com>
 <20211007104301.76693-2-galpress@amazon.com>
From:   =?UTF-8?Q?Christian_K=c3=b6nig?= <christian.koenig@amd.com>
Message-ID: <747d423e-9073-9bed-778a-292e47adf0f6@amd.com>
Date:   Thu, 7 Oct 2021 12:44:59 +0200
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Am 07.10.21 um 12:42 schrieb Gal Pressman:
> The pin callback does not necessarily have to move the memory to system
> memory, remove the sentence from the comment.
>
> Signed-off-by: Gal Pressman <galpress@amazon.com>
> ---
>   include/linux/dma-buf.h | 4 +---
>   1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
> index efdc56b9d95f..93830731a9a3 100644
> --- a/include/linux/dma-buf.h
> +++ b/include/linux/dma-buf.h
> @@ -86,9 +86,7 @@ struct dma_buf_ops {
>   	 * @pin:
>   	 *
>   	 * This is called by dma_buf_pin() and lets the exporter know that the
> -	 * DMA-buf can't be moved any more. The exporter should pin the buffer
> -	 * into system memory to make sure it is generally accessible by other
> -	 * devices.

Maybe change that to something like "Ideally the exporter should pin the 
buffer so that it is generally accessible by all devices".

Christian.

> +	 * DMA-buf can't be moved any more.
>   	 *
>   	 * This is called with the &dmabuf.resv object locked and is mutual
>   	 * exclusive with @cache_sgt_mapping.