Re: [PATCH 1/1] dmaengine: imx-sdma - correct the dma transfer residue calculation

From: Vinod Koul
Date: Fri Nov 25 2016 - 00:26:40 EST


On Tue, Oct 11, 2016 at 02:13:41PM +0300, Nandor Han wrote:
> The residue calculation was taking in consideration that dma
> transaction status will be always retrieved in the dma callback
> used to inform that dma transfer is complete. However this is not
> the case for all subsystems that use dma. Some subsystems use a
> timer to check the dma status periodically.
>
> Therefore the calculation was updated and residue is calculated
> accordingly by a) update the residue calculation taking in
> consideration the last used buffer index by using *buf_ptail* variable
> and b) chn_real_count (number of bytes transferred) is initialized to
> zero, when dma channel is created, to avoid using an uninitialized
> value in residue calculation when dma status is checked without
> waiting dma complete event.

Looks to be missed earier, so applying now

Thanks
--
~Vinod