Re: [PATCH] enic: Use dma_set_mask_and_coherent()

[Christophe JAILLET]

Le 03/01/2022 à 09:47, Christoph Hellwig a écrit :
> On Sat, Jan 01, 2022 at 03:02:45PM +0100, Christophe JAILLET wrote:
> > -	err = dma_set_mask(&pdev->dev, DMA_BIT_MASK(47));
> > +	err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(47));
> >   	if (err) {
> > +		err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
> >   		if (err) {
> >   			dev_err(dev, "No usable DMA configuration, aborting\n");
> >   			goto err_out_release_regions;
> >   		}
> >   	} else {
> >   		using_dac = 1;
>
> There is no need for the callback.  All the routines to set a DMA mask
> will only fail if the passed in mask is too small, but never if it is
> larger than what is supported.  Also the using_dac variable is not
> needed, NETIF_F_HIGHDMA can and should be set unconditionally.

Ok, thanks.
I was only aware of the 64 bits case.
The patch has already reached -next.

I'll send another patch on to of it to go one step further.

CJ