RE: [PATCH -next 3/8] dmaengine: xilinx_dma: Introduce xilinx_dma_get_residue

[Radhey Shyam Pandey]

> -----Original Message-----
> From: Vinod Koul <vkoul@xxxxxxxxxx>
> Sent: Thursday, September 26, 2019 10:48 PM
> To: Radhey Shyam Pandey <radheys@xxxxxxxxxx>
> Cc: dan.j.williams@xxxxxxxxx; Michal Simek <michals@xxxxxxxxxx>;
> nick.graumann@xxxxxxxxx; andrea.merello@xxxxxxxxx; Appana Durga
> Kedareswara Rao <appanad@xxxxxxxxxx>; mcgrof@xxxxxxxxxx;
> dmaengine@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH -next 3/8] dmaengine: xilinx_dma: Introduce
> xilinx_dma_get_residue
> 
> On 26-09-19, 05:52, Radhey Shyam Pandey wrote:
> 
> > > > +	 * VDMA and simple mode do not support residue reporting, so the
> > > > +	 * residue field will always be 0.
> > > > +	 */
> > > > +	if (chan->xdev->dma_config->dmatype == XDMA_TYPE_VDMA ||
> > > !chan->has_sg)
> > > > +		return residue;
> > >
> > > why not check this in status callback?
> > Assuming we mean to move vdma and non-sg check to
> xilinx_dma_tx_status.
> > Just a thought- Keeping this check in xilinx_dma_get_residue provides
> > an abstraction and caller can simply call this func with knowing about
> > IP config specific residue calculation. Considering this point does it
> > looks ok ?
> 
> well you are checking either way, so calling the lower level function
> only when you need it makes more sense!

Sure, will do it in v2.
> 
> --
> ~Vinod