From: "Figo.zhang" <figo1802@gmail.com>
To: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: linux-media <linux-media@vger.kernel.org>
Subject: Re: how to mmap in videobuf-dma-sg.c
Date: Thu, 21 May 2009 18:48:31 +0800 [thread overview]
Message-ID: <1242902911.12072.3.camel@myhost> (raw)
In-Reply-To: <20090521073518.1c0c0a5b@pedra.chehab.org>
On Thu, 2009-05-21 at 07:35 -0300, Mauro Carvalho Chehab wrote:
> Em Thu, 21 May 2009 12:46:04 +0800
> "Figo.zhang" <figo1802@gmail.com> escreveu:
>
> > hi,all,
> > I am puzzle that how to mmap ( V4L2_MEMORY_MMAP) in videobuf-dma-sg.c?
> >
> > In this file, it alloc the momery using vmalloc_32() , and put this
> > momery into sglist table,and then use dma_map_sg() to create sg dma at
> > __videobuf_iolock() function. but in __videobuf_mmap_mapper(), i canot
> > understand how it do the mmap?
> > why it not use the remap_vmalloc_range() to do the mmap?
>
> The answer is simple: remap_vmalloc_range() is newer than videobuf code. This
> part of the code was written back to kernel 2.4, and nobody cared to update it
> to use those newer functions, and simplify its code.
>
> If you want, feel free to propose some cleanups on it
>
>
>
> Cheers,
> Mauro
hi mauro,
Thank you!
But i canot found the similar function code of remap_vmalloc_range() in
the videobuf-dma-contig.c file. So i want to know the how is work in
__videobuf_mmap_mapper() function?
next prev parent reply other threads:[~2009-05-21 10:48 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-21 4:46 how to mmap in videobuf-dma-sg.c Figo.zhang
2009-05-21 10:35 ` Mauro Carvalho Chehab
2009-05-21 10:48 ` Figo.zhang [this message]
2009-06-10 15:06 ` Figo.zhang
2010-07-24 13:43 ` Figo.zhang
[not found] ` <AANLkTimExb4hh8K5lRCRiM0IMIgsOpCw69bFvqLlQCDc@mail.gmail.com>
2010-07-25 17:46 ` Mauro Carvalho Chehab
2010-07-26 8:16 ` Laurent Pinchart
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