From: "Carlos Rafael Giani" <crg7475@mailbox.org>
To: meta-freescale@lists.yoctoproject.org
Subject: Enabling ION with CMA heap on imx6
Date: Tue, 20 Oct 2020 10:19:03 +0200 [thread overview]
Message-ID: <1ec795f6-53b7-52c7-f2dc-05c39c2f0d03@mailbox.org> (raw)
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?
next reply other threads:[~2020-10-20 8:19 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-20 8:19 Carlos Rafael Giani [this message]
2020-10-20 11:31 ` [meta-freescale] Enabling ION with CMA heap on imx6 Otavio Salvador
2020-10-20 17:11 ` Carlos Rafael Giani
2020-10-20 11:38 ` Andrey Zhizhikin
2020-10-20 17:13 ` Carlos Rafael Giani
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