Re: 2nd attempt: help with dma_alloc_coherent() + dma_free_coherent()

From: Jeff Chua
Date: Tue Jan 08 2013 - 17:25:07 EST


On Wed, Jan 9, 2013 at 1:24 AM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Tue, Jan 8, 2013 at 9:17 AM, Jeff Chua <jeff.chua.linux@xxxxxxxxx> wrote:
>>
>> Interesting, but there are 54 lines under the kernel directories that
>> use "dma_alloc_coherent(NULL," followed by "dma_free_coherent(NULL,"
>
> As mentioned, it works on some platforms. That doesn't make it right.
>
>> So, shouldn't they be fixed as well? ... unless they are so old that
>> nobody cares anymore ...
>
> Some of the ones I saw are in MIPS or blackfin. Others probably *are*
> so old that nobody cares, and happen to work because there's iommu's
> or other things that simply don't care about the device.
>
>> # find . -exec grep -H "dma_alloc_coherent(NULL" {} \; | wc -l
>> 54
>>
>> #find . -exec grep -H "dma_free_coherent(NULL" {} \; | wc -l
>> 72
>
> Let me tell you about "git grep", so that you never need to do that
> disgusting "find -exec grep" ever again.
>
> It does threading, it's fast, and it just works.
>
> Linus

Yes, "git grep" is really fast. Cool! ... didn't know that before.

Thanks again for the help.

Jeff.
--
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/