On 10/15/17 20:29, Randy Dunlap wrote:
> On 10/15/17 20:27, Randy Dunlap wrote:
>> On 10/15/17 19:27, Marian Mihailescu wrote:
>>> After commit 7844572c633964c864d9f32dc3f2a8ffe5d70371, dma_noop_ops
>>> are built only for architectures that use it.
>>>
>>> For ARM architecture, CONFIG_DMA_NOOP_OPS is not selected, and cannot
>>> be selected.
What kernel version are you looking at?
I see that it is selected:
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -22,6 +22,7 @@ config ARM
select CLONE_BACKWARDS
select CPU_PM if (SUSPEND || CPU_IDLE)
select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS
+ select DMA_NOOP_OPS if !MMU
select EDAC_SUPPORT
select EDAC_ATOMIC_SCRUB
select GENERIC_ALLOCATOR
That's in commit ID 1c51c429f30ea10428337f3a33c12059ba59f668 from May 24, 2017.
>>> However, arch/arm/include/asm/dma-mapping.h is referencing dma_noop_ops:
>>>
>>> static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type
>>> *bus)
>>> {
>>> return IS_ENABLED(CONFIG_MMU) ? &arm_dma_ops : &dma_noop_ops;
>>> }
>>>
>>> I will let a maintainer suggest the best resolution for this :)
>>>
>>
>> add Bart and iommu mailing list.
>>
>
> and add Vladimir.
>
>
--
~Randy
