Re: [PATCH] drivers/rtc/rtc-mrst.c: Use release_mem_region after

Julia Lawall
2011-04-08T05:14:48Z

On Thu, 7 Apr 2011, Andrew Morton wrote:

> On Mon, 14 Mar 2011 22:00:25 +0100
> Julia Lawall <julia@diku.dk> wrote:
>
> > The memory allocated using request_mem_region should be released using
> > release_mem_region, not release_region.
> >
> > The semantic patch that fixes part of this problem is as follows:
> > (http://coccinelle.lip6.fr/)
> >
> > // <smpl>
> > @@
> > expression E1,E2,E3;
> > @@
> >
> > request_mem_region(E1,E2,E3)
> > ...
> > ?- release_region(E1,E2)
> > + release_mem_region(E1,E2)
> > // </smpl>
> >
> > Signed-off-by: Julia Lawall <julia@diku.dk>
> >
> > ---
> > drivers/rtc/rtc-mrst.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/rtc/rtc-mrst.c b/drivers/rtc/rtc-mrst.c
> > index b86bc32..558dd7d 100644
> > --- a/drivers/rtc/rtc-mrst.c
> > +++ b/drivers/rtc/rtc-mrst.c
> > @@ -379,7 +379,7 @@ cleanup1:
> > mrst_rtc.dev = NULL;
> > rtc_device_unregister(mrst_rtc.rtc);
> > cleanup0:
> > - release_region(iomem->start, iomem->end + 1 - iomem->start);
> > + release_mem_region(iomem->start, iomem->end + 1 - iomem->start);
> > dev_err(dev, "rtc-mrst: unable to initialise\n");
> > return retval;
> > }
> > @@ -405,7 +405,7 @@ static void __exit rtc_mrst_do_remove(struct device *dev)
> > mrst->rtc = NULL;
> >
> > iomem = mrst->iomem;
> > - release_region(iomem->start, iomem->end + 1 - iomem->start);
> > + release_mem_region(iomem->start, iomem->end + 1 - iomem->start);
> > mrst->iomem = NULL;
> >
> > mrst->dev = NULL;
>
> We may as well clean this up too.
>
> --- a/drivers/rtc/rtc-mrst.c~drivers-rtc-rtc-mrstc-use-release_mem_region-after-request_mem_region-fix
> +++ a/drivers/rtc/rtc-mrst.c
> @@ -380,7 +380,7 @@ cleanup1:
> cleanup0:
> dev_set_drvdata(dev, NULL);
> mrst_rtc.dev = NULL;
> - release_mem_region(iomem->start, iomem->end + 1 - iomem->start);
> + release_mem_region(iomem->start, resource_size(iomem));
> dev_err(dev, "rtc-mrst: unable to initialise\n");
> return retval;
> }
> @@ -406,7 +406,7 @@ static void __devexit rtc_mrst_do_remove
> mrst->rtc = NULL;
>
> iomem = mrst->iomem;
> - release_mem_region(iomem->start, iomem->end + 1 - iomem->start);
> + release_mem_region(iomem->start, resource_size(iomem));
> mrst->iomem = NULL;
>
> mrst->dev = NULL;
> _
>
> which makes one wonder why we don't have
>
> void release_resource_mem(struct resource *r)
> {
> release_mem_region(r->start, resource_size(r));
> }

Perhaps the name is not quite good, because release resource is something
different from:

void release_resource(struct resource *r)
{
release_region(r->start, resource_size(r));
}

It would be really nice to have such a wrapper for both of them, since the
code is so common, and the size computation is so error prone.

julia