From: Mauro Carvalho Chehab <mchehab@redhat.com>
To: Fabio Estevam <festevam@gmail.com>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>,
linux-media@vger.kernel.org, mchehab@infradead.org,
kernel@pengutronix.de,
Fabio Estevam <fabio.estevam@freescale.com>
Subject: Re: [PATCH] video: mx3_camera: Allocate camera object via kzalloc
Date: Mon, 19 Mar 2012 23:01:33 -0300 [thread overview]
Message-ID: <4F67E4FD.2070709@redhat.com> (raw)
In-Reply-To: <CAOMZO5AAeqHZFqpZYB_riSCQvCRSjQtR2EqpZvC5V3TRyzuWJQ@mail.gmail.com>
Em 20-02-2012 16:23, Fabio Estevam escreveu:
> On Mon, Feb 20, 2012 at 4:17 PM, Guennadi Liakhovetski
> <g.liakhovetski@gmx.de> wrote:
>> On Mon, 20 Feb 2012, Fabio Estevam wrote:
>>
>>> Align mx3_camera driver with the other soc camera driver implementations
>>> by allocating the camera object via kzalloc.
>>
>> Sorry, any specific reason, why you think this "aligning" is so important?
>
> Not really.
>
> Just compared it with all other soc camera drivers I found and
> mx3_camera was the only one that uses "vzalloc"
>
> Any specific reason that requires mx3_camera to use "vzalloc" instead
> of "kzalloc"?
kzalloc() is more restrictive than vzalloc(). With v*alloc, it will allocate
a virtual memory area, with can be discontinuous, while kzalloc will get
a continuous area.
The DMA logic need to be prepared for virtual memory, if v*alloc() is used
(e. g. using videobuf2-vmalloc).
As it is currently including media/videobuf2-dma-contig.h, I this patch
makes sense on my eyes.
>
> Tested with kzalloc and it worked fine on my mx31pdk.
If the driver is working with vzalloc, then maybe it is due to some arch-specific
implementation for v*alloc. It shouldn't be working like that.
Regards,
Mauro
>
> Regards,
>
> Fabio Estevam
> --
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next prev parent reply other threads:[~2012-03-20 2:02 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-20 18:11 [PATCH] video: mx3_camera: Allocate camera object via kzalloc Fabio Estevam
2012-02-20 18:17 ` Guennadi Liakhovetski
2012-02-20 18:23 ` Fabio Estevam
2012-03-20 2:01 ` Mauro Carvalho Chehab [this message]
2012-03-20 7:57 ` Guennadi Liakhovetski
2012-03-20 12:37 ` Fabio Estevam
2012-03-20 12:40 ` Guennadi Liakhovetski
2012-03-20 12:45 ` Fabio Estevam
2012-03-20 13:11 ` Guennadi Liakhovetski
2012-03-20 13:20 ` AverTV Volar HD PRO : a return case Sril
2012-03-20 12:53 ` [PATCH] video: mx3_camera: Allocate camera object via kzalloc Mauro Carvalho Chehab
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