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From: Hans Verkuil <hverkuil@xs4all.nl>
To: Ma Haijun <mahaijuns@gmail.com>,
	linux-media@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Mauro Carvalho Chehab <m.chehab@samsung.com>,
	Al Viro <viro@ZenIV.linux.org.uk>
Subject: Re: [media] videobuf-dma-contig: fix vm_iomap_memory() call
Date: Fri, 28 Mar 2014 10:28:46 +0100	[thread overview]
Message-ID: <533540CE.8070703@xs4all.nl> (raw)
In-Reply-To: <1395918426-27787-1-git-send-email-mahaijuns@gmail.com>

On 03/27/2014 12:07 PM, Ma Haijun wrote:
> Hi all,
> 
> This is a trivial fix, but I think the patch itself has problem too. 
> The function requires a phys_addr_t, but we feed it with a dma_handle_t.
> AFAIK, this implicit conversion does not always work.
> Can I use virt_to_phys(mem->vaddr) to get the physical address instead?
> (mem->vaddr and mem->dma_handle are from dma_alloc_coherent)

Does this actually fail? With what driver and on what hardware?

I ask because I am very reluctant to make any changes to videobuf. It is
slowly being replaced by the vastly superior videobuf2 framework. Existing
drivers in the kernel still using the old videobuf seem to work just fine
(or at least as fine as videobuf allows you to be).

Regards,

	Hans

> 
> Regards
> 
> Ma Haijun
> 
> Ma Haijun (1):
>   [media] videobuf-dma-contig: fix incorrect argument to
>     vm_iomap_memory() call
> 
>  drivers/media/v4l2-core/videobuf-dma-contig.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 


  reply	other threads:[~2014-03-28  9:42 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-03-27 11:07 [media] videobuf-dma-contig: fix vm_iomap_memory() call Ma Haijun
2014-03-28  9:28 ` Hans Verkuil [this message]
2014-03-28 16:58   ` Ma Haijun

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