Re: [PATCH v2 1/4] dmaengine: xilinx_dma: populate dma caps properly

[Vinod Koul]

On Mon, Jan 08, 2018 at 10:52:01AM +0000, Appana Durga Kedareswara Rao wrote:
> Hi Vinod,
> 
> 	Thanks for the review.... 
> <Snip>
> >> @@ -2398,6 +2398,7 @@ static int xilinx_dma_chan_probe(struct
> >xilinx_dma_device *xdev,
> >>  		chan->direction = DMA_MEM_TO_DEV;
> >>  		chan->id = chan_id;
> >>  		chan->tdest = chan_id;
> >> +		xdev->common.directions = BIT(DMA_MEM_TO_DEV);
> >>
> >>  		chan->ctrl_offset = XILINX_DMA_MM2S_CTRL_OFFSET;
> >>  		if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) { @@ -
> >2415,6
> >> +2416,7 @@ static int xilinx_dma_chan_probe(struct xilinx_dma_device *xdev,
> >>  		chan->direction = DMA_DEV_TO_MEM;
> >>  		chan->id = chan_id;
> >>  		chan->tdest = chan_id - xdev->nr_channels;
> >> +		xdev->common.directions |= BIT(DMA_DEV_TO_MEM);
> >>
> >>  		chan->ctrl_offset = XILINX_DMA_S2MM_CTRL_OFFSET;
> >>  		if (xdev->dma_config->dmatype == XDMA_TYPE_VDMA) { @@ -
> >2629,6
> >> +2631,8 @@ static int xilinx_dma_probe(struct platform_device *pdev)
> >>  		dma_cap_set(DMA_PRIVATE, xdev->common.cap_mask);
> >>  	}
> >>
> >> +	xdev->common.dst_addr_widths = BIT(addr_width / 8);
> >> +	xdev->common.src_addr_widths = BIT(addr_width / 8);
> >
> >Do you not support trf of 1byte, 2 bytes, or 4 bytes wide transfers? What is value
> >of addr_width here typically? Usually controllers can support different widths and
> >this is a surprise that you support only one value
> 
> Controller supports address width of 32 and 64.

Then this should have both 32 and 64 values here

> addr_width typical values are 32-bit or 64-bit .
> Here addr_width is device-tree parameter...
> my understanding of src_addr_widths/dst_addr_widths is, it is a bit mask of the 
> address with in bytes that DMA supports, please correct if my understanding is wrong.
> 
> Regards,
> Kedar.
> 
> >
> >--
> >~Vinod

-- 
~Vinod