lkml.org 
[lkml]   [2008]   [Jun]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [PATCH v4 4/6] dmaengine: Make DMA Engine menu visible for AVR32 users
Date
On Thursday 26 June 2008, Dan Williams wrote:
> I agree with removing the arch dependency, and I do not think we
> necessarily need to add HAVE_DMA_ENGINE.

I think a HAVE_DMA_ENGINE would be better than what you're doing
below: moving the arch dependency into the network code, and
adding this !HIGHMEM64G thing (which is really just a more subtle
arch dependency).

Note that HAS_DMA is very different from having DMA engine support...
one is a specific interface, the other is the generic mechanism with
any of its numerous (and often peripheral-specific) interfaces.


> Taking an example from libata
> the SATA_FSL driver depends on FSL_SOC but the menuconfig for ATA does
> not. We can use "depends on HAS_DMA" to make the menu disappear on
> archs that will never have a dmaegine. So I propose the following:
>
> diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
> index 6239c3d..e4dd006 100644
> --- a/drivers/dma/Kconfig
> +++ b/drivers/dma/Kconfig
> @@ -4,13 +4,14 @@
>
> menuconfig DMADEVICES
> bool "DMA Engine support"
> - depends on (PCI && X86) || ARCH_IOP32X || ARCH_IOP33X || ARCH_IOP13XX || PPC
> - depends on !HIGHMEM64G
> + depends on !HIGHMEM64G && HAS_DMA
> help
> DMA engines can do asynchronous data transfers without
> involving the host CPU. Currently, this framework can be
> used to offload memory copies in the network stack and
> - RAID operations in the MD driver.
> + RAID operations in the MD driver. This menu only presents
> + DMA Device drivers supported by the configured arch, it may
> + be empty in some cases.
>
> if DMADEVICES
>
> @@ -55,10 +56,12 @@ comment "DMA Clients"
> config NET_DMA
> bool "Network: TCP receive copy offload"
> depends on DMA_ENGINE && NET
> + default (INTEL_IOATDMA || FSL_DMA)
> help
> This enables the use of DMA engines in the network stack to
> offload receive copy-to-user operations, freeing CPU cycles.
> - Since this is the main user of the DMA engine, it should be enabled;
> - say Y here.
> +
> + Say Y here if you enabled INTEL_IOATDMA or FSL_DMA, otherwise
> + say N.
>
> endif
>
>
>




\
 
 \ /
  Last update: 2008-06-27 19:37    [W:0.216 / U:0.132 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site