Re: [PATCH v2 4/5] riscv: Select ARCH_DMA_DEFAULT_COHERENT

Palmer Dabbelt
2023-03-15T02:08:17Z

On Thu, 23 Feb 2023 14:20:27 PST (-0800), Conor Dooley wrote:
> On Thu, Feb 23, 2023 at 11:36:43AM +0000, Jiaxun Yang wrote:
>> For riscv our assumption is unless a device states it is non-coherent,
>> we take it to be DMA coherent.
>>
>> Select ARCH_DMA_DEFAULT_COHERENT to ensure dma_default_coherent
>> is always initialized to true.
>>
>> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
>> ---
>> arch/riscv/Kconfig | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
>> index 1d46a268ce16..b71ce992c0c0 100644
>> --- a/arch/riscv/Kconfig
>> +++ b/arch/riscv/Kconfig
>> @@ -233,6 +233,7 @@ config LOCKDEP_SUPPORT
>>
>> config RISCV_DMA_NONCOHERENT
>> bool
>> + select ARCH_DMA_DEFAULT_COHERENT
>
> Since we are always coherent by default, I feel like you should put this
> in the main "config RISCV" section, where OF_DMA_DEFAULT_COHERENT
> currently is, no?

Seems reasonable to me. With that

Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>

as I'm assuming these should all stay together.

Thanks!

>
> Wouldn't bother respinning for that unless the dma folk have comments
> for you.
>
>> select ARCH_HAS_DMA_PREP_COHERENT
>> select ARCH_HAS_SETUP_DMA_OPS
>> select ARCH_HAS_SYNC_DMA_FOR_CPU
>> --
>> 2.37.1 (Apple Git-137.1)
>>