Re: [Xen-devel] [PATCH v4 3/7] [RFC] arm/arm64: introduce is_dma_coherent

From: David Vrabel
Date: Mon Oct 27 2014 - 07:02:23 EST


On 25/10/14 17:15, Stefano Stabellini wrote:
> On Sat, 25 Oct 2014, Ian Campbell wrote:
>> On Sat, 2014-10-25 at 14:29 +0100, Stefano Stabellini wrote:
>>>
>>> Your suggestions and looking more at the code gave me another idea, that
>>> I think is clean and at the same time suitable for 3.18.
>>> What do you think of the following? It is simple, self-contained and
>>> doesn't need a new flag in struct device.
>>
>> of_dma_is_coherent looks to be quite expensive though (walks up the
>> Device Tree doing strcmps on each property of each node until it finds
>> the one it is looking for.
>
> It takes spin_locks too!
> Too bad, I think I'll have to ditch it. In that case I'l try the new
> flag in struct device approach.

If you're having to make changes to struct device, this is looking like
a series for 3.19 (not 3.18).

David
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/