On Thu, 2008-06-26 at 07:46 -0700, Haavard Skinnemoen wrote: > Adrian Bunk <bunk@xxxxxxxxxx> wrote: > > That discussion is mixing two different things I suggested besides other > > things before the Kconfig file was added [1]: > > - have DMA_ENGINE select'ed when a device gets enabled by the user, > > and not be an independent option > > - switch to menuconfig and don't offer an empty kconfig menu > > > > There seems to be no disagreement about the former (which could > > otherwise easily lead to users mistakenly enabling NET_DMA). > > > > The latter is more a cosmetical kconfig UI thing, and I already said > > back then that it "could be dropped if it would become a problem" [2]. > > Ok, thanks for explaining. The menu does appear empty if I remove the > architecture dependency without adding the driver...if that's a problem > maybe we should do the HAVE_DMA_DEVICE thing... > > > So if you want to remove the architecture dependency from the DMADEVICES > > menu that's OK with me. > > Ok, I'm gonna wait for Dan and others to respond. If it's fine with > them, I'll post a patch removing the arch dependency. I agree with removing the arch dependency, and I do not think we necessarily need to add HAVE_DMA_ENGINE. 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 -- To unsubscribe from this list: send the line "unsubscribe linux-embedded" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
