[PATCH v2] io-mapping: Indicate mapping failure

[Daniel Vetter]

On Tue, Jul 21, 2020 at 11:24 PM Andrew Morton
<akpm at linux-foundation.org> wrote:
>
> On Tue, 21 Jul 2020 21:02:44 +0000 "Ruhl, Michael J" <michael.j.ruhl at intel.com> wrote:
>
> > >--- a/include/linux/io-mapping.h~io-mapping-indicate-mapping-failure-fix
> > >+++ a/include/linux/io-mapping.h
> > >@@ -107,9 +107,12 @@ io_mapping_init_wc(struct io_mapping *io
> > >                resource_size_t base,
> > >                unsigned long size)
> > > {
> > >+    iomap->iomem = ioremap_wc(base, size);
> > >+    if (!iomap->iomem)
> > >+            return NULL;
> > >+
> >
> > This does make more sense.
> >
> > I am confused by the two follow up emails I just got.
>
> One was your original patch, the other is my suggested alteration.
>
> > Shall I resubmit, or is this path (if !iomap->iomem) return NULL)
> > now in the tree.
>
> All is OK.  If my alteration is acceptable (and, preferably, tested!)
> then when the time comes, I'll fold it into the base patch, add a
> note indicating this change and shall then send it to Linus.

Your alternative also matches the other implementation of
io_mapping_init_wc, I was kinda tempted to do that suggestion too just
because of that. But then didn't send out that email.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch