Re: [PATCH v3 04/24] dmaengine: qcom_hidma: Remove call to memset after dmam_alloc_coherent

From: Sinan Kaya
Date: Tue Jul 16 2019 - 11:10:20 EST


On 7/16/2019 7:35 AM, Robin Murphy wrote:
> On 15/07/2019 16:17, Sinan Kaya wrote:
>> On 7/15/2019 1:43 AM, Fuqian Huang wrote:
>>> Should I rewrite the commit log? Just mention that dma_alloc_coherent
>>> has already
>>> zeroed the memory and not to reference the commit?
>>
>> I'd like to hear from Robin Murphy that arm smmu driver follows this as
>> well.
>
> I'd be lying if I said it did.
>
> ...but only because that's never been part of the SMMU driver's
> responsibility either way. The iommu-dma layer however, and thus the
> respective arm64 iommu_dma_ops, has always zeroed allocations right from
> its inception.
>
> 518a2f1925c3 was just cleaning up the last of the stragglers which
> *weren't* already clearing buffers anyway, such that we could formalise
> that behaviour into the API.

Thanks for confirming the behavior for arm64 arch.

Acked-by: Sinan Kaya <okaya@xxxxxxxxxx>