Re: [PATCH v5 0/3] dmaengine: ti: edma: Polled completion support

[Vinod Koul <vkoul@kernel.org>]

On 16-07-19, 11:26, Peter Ujfalusi wrote:
> Hi,
> 
> Changes since v4:
> - Split the DMA_COMPLETE and !txstate check as Vinod suggested
> 
> Change since v3:
> - fix DMA pointer tracking for memcpy
> - completion polling is only done when it is asked by not providing
>   DMA_PREP_INTERRUPT for memcpy
> 
> Changes since v2:
> - Fix typo in the comment for patch 0
> 
> Changes since v1:
> - Cleanup patch for the array register handling
> - typo fixed in patch2 commit message
> 
> The code around the array register access was pretty confusing for the first
> look, so clean them up first then use the cleaner way in the polled handling.
> 
> When a DMA client driver does not set the DMA_PREP_INTERRUPT because it
> does not want to use interrupts for DMA completion or because it can not
> rely on DMA interrupts due to executing the memcpy when interrupts are
> disabled it will poll the status of the transfer.
> 
> Since we can not tell from any EDMA register that the transfer is
> completed, we can only know that the paRAM set has been sent to TPTC for
> processing we need to check the residue of the transfer, if it is 0 then
> the transfer is completed.
> 
> The polled completion can bve tested by applying:
> https://patchwork.kernel.org/patch/10966499/
> 
> Enabling the memcpy for EDMA and run the dmatest with polled = 1.
> 
> Or, enable the EDMA memcpy support and boot up any dra7 family device with
> display enabled. The workaround for DMM errata i878 uses polled DMA memcpy.

Applied, thanks. Fixed typo in 2nd patch while at it

-- 
~Vinod