Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm

[mirror_ubuntu-artful-kernel.git] / arch / arm / mm / Kconfig

diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 4f68659abe6c5ac9900022d2db21e7fb9809c126..60cdfdc151aa3fb934e8b465fac261b92c46a3c9 100644 (file)
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -1049,8 +1049,8 @@ config ARM_L1_CACHE_SHIFT
        default 5
 
 config ARM_DMA_MEM_BUFFERABLE
-       bool "Use non-cacheable memory for DMA" if (CPU_V6 || CPU_V6K) && !CPU_V7
-       default y if CPU_V6 || CPU_V6K || CPU_V7
+       bool "Use non-cacheable memory for DMA" if (CPU_V6 || CPU_V6K || CPU_V7M) && !CPU_V7
+       default y if CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M
        help
          Historically, the kernel has used strongly ordered mappings to
          provide DMA coherent memory.  With the advent of ARMv7, mapping
@@ -1065,6 +1065,10 @@ config ARM_DMA_MEM_BUFFERABLE
          and therefore turning this on may result in unpredictable driver
          behaviour.  Therefore, we offer this as an option.
 
+         On some of the beefier ARMv7-M machines (with DMA and write
+         buffers) you likely want this enabled, while those that
+         didn't need it until now also won't need it in the future.
+
          You are recommended say 'Y' here and debug any affected drivers.
 
 config ARM_HEAVY_MB