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
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