Re: [PATCH v2 2/4] devm: fix ioremap_cache() usage

[Arnd Bergmann <arnd@arndb.de>]

On Saturday 30 May 2015 14:16:28 Dan Williams wrote:
> On Sat, May 30, 2015 at 1:52 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> > On Saturday 30 May 2015, Dan Williams wrote:
> >> @@ -154,7 +148,7 @@ void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res)
> >>         }
> >>
> >>         if (res->flags & IORESOURCE_CACHEABLE)
> >> -               dest_ptr = devm_ioremap(dev, res->start, size);
> >> +               dest_ptr = devm_ioremap_cache(dev, res->start, size);
> >>         else
> >>                 dest_ptr = devm_ioremap_nocache(dev, res->start, size);
> >
> > I think the existing uses of IORESOURCE_CACHEABLE are mostly bugs, so changing
> > the behavior here may cause more problems than it solves.
> >
> 
> Ok, but that effectively makes devm_ioremap_resource() unusable for
> the cached case.  How about introducing devm_ioremap_cache_resource(),
> and cleaning up devm_ioremap_resource() to stop pretending that it is
> honoring the memory type of the resource?

I was thinking the opposite approach and basically removing all uses
of IORESOURCE_CACHEABLE from the kernel. There are only a handful of
them.and we can probably replace them all with hardcoded ioremap_cached()
calls in the cases they are actually useful

	Arnd

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