Re: [PATCH] add raw video support for Samsung SUR40 touchscreen

[Hans Verkuil <hverkuil@xs4all.nl>]

On 02/04/15 11:08, Florian Echtler wrote:
> Hello Hans,
> 
> On 04.02.2015 09:08, Hans Verkuil wrote:
>> I remain very skeptical about the use of dma-contig (or dma-sg for that
>> matter). Have you tried using vmalloc and check if the USB core isn't
>> automatically using DMA transfers for that?
>>
>> Basically I would like to see proof that vmalloc is not an option before
>> allowing dma-contig (or dma-sg if you can figure out why that isn't
>> working).
>>
>> You can also make a version with vmalloc and I'll merge that, and then
>> you can look more into the DMA issues. That way the driver is merged,
>> even if it is perhaps not yet optimal, and you can address that part later.
> OK, that sounds sensible, I will try that route. When using
> videobuf2-vmalloc, what do I pass back for alloc_ctxs in queue_setup?

vmalloc doesn't need those, so you can just drop any alloc_ctx related code.

Regards,

	Hans