From: "Carlos Rafael Giani" <crg7475@mailbox.org>
To: meta-freescale@lists.yoctoproject.org
Subject: Re: [meta-freescale] Enabling ION with CMA heap on imx6
Date: Tue, 20 Oct 2020 19:11:58 +0200 [thread overview]
Message-ID: <3b8b2850-9d63-87f5-af30-60c4b8368604@mailbox.org> (raw)
In-Reply-To: <CAP9ODKqf_6Yz8avbhWPdFCNrgNDAM2_6=bpi20d3xN4bDnQzEA@mail.gmail.com>
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For i.MX8 it is enabled already.
On 20.10.20 13:31, Otavio Salvador wrote:
> Hello Carlos,
>
> Em ter., 20 de out. de 2020 às 05:19, Carlos Rafael Giani via
> lists.yoctoproject.org <crg7475=mailbox.org@lists.yoctoproject.org>
> escreveu:
>> On i.MX6 machines, it is currently not possible to use the ION
>> allocator. However, there is no hardware limitation that requires ION to
>> be disabled.
>>
>> If ION were enabled, with a CMA heap, then it would be possible for
>> userspace to allocate DMA-BUF buffers. I could then enable the ion
>> packageconfig in the libimxdmabuffer recipe.
>>
>> The defconfig only needs these additions:
>>
>> CONFIG_ION=y
>> CONFIG_ION_SYSTEM_HEAP=y
>> CONFIG_ION_CMA_HEAP=y
>>
>> I tried it out, worked fine.
>>
>> Using DMA-BUF for allocating physically contiguous memory (via CMA) is
>> preferable over using other allocators (like the ones from the VPU, IPU
>> etc.) since it allows for proper buffer sharing, ownership transfer, is
>> based on FDs (though physical address are accessible via an NXP
>> extension), and there are extensions in OpenCL, OpenGL etc. for
>> importing DMA-BUF. V4L2 also has DMA-BUF support.
>>
>> Opinions?
> Please prepare the PR for it; also see if i.MX8 couldn't also benefit from it.
>
>
>
>
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next prev parent reply other threads:[~2020-10-20 17:12 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-20 8:19 Enabling ION with CMA heap on imx6 Carlos Rafael Giani
2020-10-20 11:31 ` [meta-freescale] " Otavio Salvador
2020-10-20 17:11 ` Carlos Rafael Giani [this message]
2020-10-20 11:38 ` Andrey Zhizhikin
2020-10-20 17:13 ` Carlos Rafael Giani
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