Re: [PATCH v3 1/5] drivers: provide devm_platform_get_and_ioremap_resource()

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Mar 17, 2020 at 08:35:16PM +0100, Geert Uytterhoeven wrote:
> Hi Greg,
> 
> On Tue, Mar 17, 2020 at 8:20 PM Greg KH <gregkh@linuxfoundation.org> wrote:
> > On Sun, Mar 15, 2020 at 10:05:21PM +0800, Dejin Zheng wrote:
> > > Since commit "drivers: provide devm_platform_ioremap_resource()",
> > > it was wrap platform_get_resource() and devm_ioremap_resource() as
> > > single helper devm_platform_ioremap_resource(). but now, many drivers
> > > still used platform_get_resource() and devm_ioremap_resource()
> > > together in the kernel tree. The reason can not be replaced is they
> > > still need use the resource variables obtained by platform_get_resource().
> > > so provide this helper.
> > >
> > > Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
> > > Suggested-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
> > > Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
> > > ---
> > > v2 -> v3:
> > >       - rename the function to
> > >         devm_platform_get_and_ioremap_resource() by Sergei's suggestion.
> > >       - make the last parameter res as optional by Geert's suggestion.
> > >
> > > v1 -> v2:
> > >       - No change.
> > >
> > >  drivers/base/platform.c         | 22 ++++++++++++++++++++++
> > >  include/linux/platform_device.h |  3 +++
> > >  2 files changed, 25 insertions(+)
> > >
> > > diff --git a/drivers/base/platform.c b/drivers/base/platform.c
> > > index 7fa654f1288b..9f6a78f79235 100644
> > > --- a/drivers/base/platform.c
> > > +++ b/drivers/base/platform.c
> > > @@ -62,6 +62,28 @@ struct resource *platform_get_resource(struct platform_device *dev,
> > >  EXPORT_SYMBOL_GPL(platform_get_resource);
> > >
> > >  #ifdef CONFIG_HAS_IOMEM
> > > +/**
> > > + * devm_platform_get_and_ioremap_resource - call devm_ioremap_resource() for a
> > > + *                                       platform device and get resource
> > > + *
> > > + * @pdev: platform device to use both for memory resource lookup as well as
> > > + *        resource management
> > > + * @index: resource index
> > > + * @res: get the resource
> > > + */
> > > +void __iomem *
> > > +devm_platform_get_and_ioremap_resource(struct platform_device *pdev,
> > > +                             unsigned int index, struct resource **res)
> > > +{
> > > +     struct resource *r;
> > > +
> > > +     r = platform_get_resource(pdev, IORESOURCE_MEM, index);
> > > +     if (res)
> > > +             *res = r;
> >
> > What happens if that call fails?  Shouldn't that be checked?
> 
> Then devm_ioremap_resource() will print an error message, and return
> an error.
> It's designed to be pipelined that way, so you have to check for an error
> only once.

Ok, thanks.  Can I get an ack/reviewed-by for this series then?

thanks,

greg k-h