[PATCH 1/5] [media] rockchip/rga: v4l2 m2m support

Jacob Chen jacobchen110 at gmail.com
Tue Jun 27 08:45:14 PDT 2017

Hi Tomasz,
Yeah, the comments are wrong, i will correct it

>> +        */
>> +       pages = (unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
> This is rather unfortunate and you should expect failures here on
> actively used systems with uptime longer than few hours. Changing this
> to dma_alloc_coherent() and enabling CMA _might_ give you a bit better
> success rate, but...
> Normally, this kind of (scatter-gather capable) hardware would allow
> some kind of linking of separate pages, e.g. last entry in the page
> would point to the next page, or something like that. Doesn't this RGA
> block have something similar?

Thx for pointing it out ! : )

I looked RGA drvier used in rockchip android and i find it use
kmalloc, so i think it might support separate pages.
I will test it.

> Best regards,
> Tomasz

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