dmaengine: remove arch dependency from DMADEVICES

The dependency is redundant since all drivers set their specific arch
dependencies.  The NET_DMA option is modified to be enabled only on platforms
where it is known to have a positive effect.  HAS_DMA is added as an explicit
dependency for the DMADEVICES menu.

Acked-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 8 insertions, 5 deletions

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 6239c3df30ac..e4dd0065da33 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