[PATCH v3 09/13] device core: Introduce multiple dma pfn offsets

[Jim Quinlan]

Hi Andy,

On Thu, Jun 4, 2020 at 11:05 AM Andy Shevchenko
<andriy.shevchenko at linux.intel.com> wrote:
>
> On Thu, Jun 04, 2020 at 10:35:12AM -0400, Jim Quinlan wrote:
> > On Thu, Jun 4, 2020 at 9:53 AM Nicolas Saenz Julienne
> > <nsaenzjulienne at suse.de> wrote:
> > > On Wed, 2020-06-03 at 15:20 -0400, Jim Quinlan wrote:
>
> ...
>
> > > > +     phys = virt_to_phys(ret);
> > > > +     pfn =  phys >> PAGE_SHIFT;
> > >
> > > nit: not sure it really pays off to have a pfn variable here.
> > Did it for readability; the compiler's optimization should take care
> > of any extra variables.  But I can switch if you insist.
>
> One side note: please, try to get familiar with existing helpers in the kernel.
> For example, above line is like
>
>         pfn = PFN_DOWN(phys);
I just used the term in the original code; will change to PFN_DOWN().

>
> ...
>
> > > > +     if (!WARN_ON(!dev) && dev->dma_pfn_offset_map)
>
> > > > +             *dma_handle -= PFN_PHYS(
> > > > +                     dma_pfn_offset_from_phys_addr(dev, phys));
>
> Don't do such indentation, esp. we have now 100! :-)

Got it.  Thanks,
Jim Quinlan
>
> --
> With Best Regards,
> Andy Shevchenko
>
>