On Tue, Oct 06, 2020 at 08:35:54AM +0100, Christoph Hellwig wrote:
> > + WARN_ON(!IS_ENABLED(CONFIG_DMA_VIRT_OPS) && !dma_device);
> > + if (!dma_device) {
> > /*
> > - * The caller did not provide custom DMA operations. Use the
> > - * DMA mapping operations of the parent device.
> > + * If the caller does not provide a DMA capable device then the
> > + * IB device will be used. In this case the caller should fully
> > + * setup the ibdev for DMA. This usually means using
> > + * dma_virt_ops.
> > */
> > + device->dev.dma_ops = &dma_virt_ops;
> > + dma_device = &device->dev;
>
> The lack of the if probably means this will fail to link now when
> CONFIG_DMA_VIRT_OPS is not set. This also seems to not remove the
> dma_virt_ops assignment in the callers.
I expect to see this during driver development/testing. It is not worth
to make if() case id device won't be operable.
Thanks
