On Fri, 24 Nov 2023 17:02:35 +0100, Amelie Delaunay wrote:
> Source and destination data buffers are allocated with GPF_KERNEL flag.
> It means that, if the DDR is more than 2GB, buffers can be allocated above
> the 32-bit addressable space. In this case, and if the dma controller is
> only 32-bit compatible, swiotlb bounce buffer, located in the 32-bit
> addressable space, is used and introduces a memcpy.
>
> To prevent this extra memcpy, due to swiotlb bounce buffer use because
> source or destination data buffer is allocated above the 32-bit addressable
> space, force source and destination data buffers allocation with GPF_DMA
> instead, when nobounce parameter is true.
>
> [...]
Applied, thanks!
[1/1] dmaengine: dmatest: prevent using swiotlb buffer with nobounce parameter
commit: 70f008fb3ea9bd2e6727eebc858405acd49a212b
Best regards,
--
~Vinod
