RE: [PATCH 4/8] ARM: dma-mapping: implement dma sg methods on top of generic dma ops

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hello,

On Monday, June 20, 2011 4:40 PM Russell King - ARM Linux wrote:

> On Mon, Jun 20, 2011 at 09:50:09AM +0200, Marek Szyprowski wrote:
> > This patch converts all dma_sg methods to be generic (independent of the
> > current DMA mapping implementation for ARM architecture). All dma sg
> > operations are now implemented on top of respective
> > dma_map_page/dma_sync_single_for* operations from dma_map_ops structure.
> 
> No.  We really don't want to do this.

I assume you want to keep the current design for performance reasons?

It's really not a problem for me. I can change my patches to keep 
arm_dma_*_sg_* functions and create some stubs for dmabounce version.

> If we want to move the dsb() out of the mapping functions (which I
> have a patch for) to avoid doing a dsb() on each and every sg segment,
> then we must not use the generic stuff.

Ok, specialized (optimized) version of dma_*_sg_* operations are definitely
better. The current version just calls respective dma_single_* operations in
a loop, so in my patches I decided to create some generic version just to
simplify the code. 

Best regards
-- 
Marek Szyprowski
Samsung Poland R&D Center



--
To unsubscribe from this list: send the line "unsubscribe linux-arch" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Kernel]     [Kernel Newbies]     [x86 Platform Driver]     [Netdev]     [Linux Wireless]     [Netfilter]     [Bugtraq]     [Linux Filesystems]     [Yosemite Discussion]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Device Mapper]

  Powered by Linux