Re: [Xen-devel] [PATCH 5/9] drm/xen/xen_drm_front_gem.c: Convert to use vm_insert_range

From: Matthew Wilcox
Date: Mon Nov 19 2018 - 07:29:37 EST


On Mon, Nov 19, 2018 at 01:02:46PM +0200, Oleksandr Andrushchenko wrote:
> On 11/19/18 12:42 PM, Souptick Joarder wrote:
> > On Mon, Nov 19, 2018 at 3:22 PM Oleksandr Andrushchenko
> > <andr2000@xxxxxxxxx> wrote:
> > > > - unsigned long addr = vma->vm_start;
> > > > - int i;
> > > > + int err;
> > > I would love to keep ret, not err
> > Sure, will add it in v2.
> > But I think, err is more appropriate here.
>
> I used "ret" throughout the driver, so this is just to remain consistent:
>
> grep -rnw err drivers/gpu/drm/xen/ | wc -l
> 0
> grep -rnw ret drivers/gpu/drm/xen/ | wc -l
> 204

It's your driver, so that's fine. The reason we chose 'err' over 'ret'
is that there's a history of errno vs VM_FAULT_xxx code confusion in
this area. Naming a variable 'err' makes it clear this is an errno and
not a vm_fault_t.

> > > With the above fixed,
> > >
> > > Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>

Thanks.