Re: [RESEND PATCH v3 0/6] STM32 DMA-MDMA chaining feature

Vinod Koul
2022-09-04T17:18:54Z

On 29-08-22, 17:46, Amelie Delaunay wrote:
> This patchset (re)introduces STM32 DMA-MDMA chaining feature.
>
> As the DMA is not able to generate convenient burst transfer on the DDR,
> it penalises the AXI bus when accessing the DDR. While it accesses
> optimally the SRAM. The DMA-MDMA chaining then consists in having an SRAM
> buffer between DMA and MDMA, so the DMA deals with peripheral and SRAM,
> and the MDMA with SRAM and DDR.
>
> The feature relies on the fact that DMA channel Transfer Complete signal
> can trigger a MDMA channel transfer and MDMA can clear the DMA request by
> writing to DMA Interrupt Clear register.
>
> A deeper introduction can be found in patch 1.
>
> Previous implementation [1] has been dropped as nacked.
> Unlike this previous implementation (where all the stuff was embedded in
> stm32-dma driver), the user (in peripheral drivers using dma) has now to
> configure the MDMA channel.

Applied, thanks

--
~Vinod