Re: [PATCH v3 04/18] driver core: platform: Add driver dma ownership management

[Jason Gunthorpe]

On Tue, Dec 07, 2021 at 10:57:25AM +0800, Lu Baolu wrote:
> On 12/6/21 11:06 PM, Jason Gunthorpe wrote:
> > On Mon, Dec 06, 2021 at 06:36:27AM -0800, Christoph Hellwig wrote:
> > > I really hate the amount of boilerplate code that having this in each
> > > bus type causes.
> > +1
> > 
> > I liked the first version of this series better with the code near
> > really_probe().
> > 
> > Can we go back to that with some device_configure_dma() wrapper
> > condtionally called by really_probe as we discussed?
> > 
> 
> Are you talking about below change?
> 
> diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> index 68ea1f949daa..368f9e530515 100644
> +++ b/drivers/base/dd.c
> @@ -577,7 +577,13 @@ static int really_probe(struct device *dev, struct
> device_driver *drv)
>  	if (dev->bus->dma_configure) {
>  		ret = dev->bus->dma_configure(dev);
>  		if (ret)
> -			goto probe_failed;
> +			goto pinctrl_bind_failed;
> +
> +		if (!drv->no_kernel_dma) {
> +			ret = iommu_device_set_dma_owner(dev, DMA_OWNER_DMA_API, NULL);
> +			if (ret)
> +				goto pinctrl_bind_failed;
> +                }
>  	}

Yes, the suggestion was to put everything that 'if' inside a function
and then of course a matching undo function.

Jason