Re: [PATCH 1/2] mtd: denali_dt: Use devm_ioremap_resource()

[Dinh Nguyen <dinguyen@altera.com>]

On Mon, 2014-02-24 at 01:08 +0000, Jingoo Han wrote:
> On Sunday, February 23, 2014 11:20 AM, Brian Norris wrote:
> > On Wed, Feb 12, 2014 at 11:29:42AM +0900, Jingoo Han wrote:
> > > Use devm_ioremap_resource() in order to make the code
> > > simpler, and remove redundant return value check of
> > > platform_get_resource_byname() because the value is
> > > checked by devm_ioremap_resource().
> > >
> > > Signed-off-by: Jingoo Han <jg1.han@samsung.com>
> > > ---
> > >  drivers/mtd/nand/denali_dt.c |   39 ++++++++-------------------------------
> > >  1 file changed, 8 insertions(+), 31 deletions(-)
> > >
> > > diff --git a/drivers/mtd/nand/denali_dt.c b/drivers/mtd/nand/denali_dt.c
> > > index babb02c..35cb17f 100644
> > > --- a/drivers/mtd/nand/denali_dt.c
> > > +++ b/drivers/mtd/nand/denali_dt.c
> > > @@ -30,24 +30,6 @@ struct denali_dt {
> > >  	struct clk		*clk;
> > >  };
> > >
> > > -static void __iomem *request_and_map(struct device *dev,
> > > -				     const struct resource *res)
> > > -{
> > > -	void __iomem *ptr;
> > > -
> > > -	if (!devm_request_mem_region(dev, res->start, resource_size(res),
> > > -				     "denali-dt")) {
> > > -		dev_err(dev, "unable to request %s\n", res->name);
> > > -		return NULL;
> > > -	}
> > > -
> > > -	ptr = devm_ioremap_nocache(dev, res->start, resource_size(res));
> > 
> > Your code here is not a direct replacement; Dinh originally used the
> > _nocache variant of ioremap, but you are replacing it with the standard
> > one. There is no difference between the two on several ARCH's, but I
> > can't guarantee that your patch is safe without confirmation/testing. So
> > I will not take this without an Ack or Tested-by from someone
> > knowledgeable about denali.
> 

Sorry that it took a while to get around to this. But I was able to test
the patch and it looks fine.

Tested-by: Dinh Nguyen <dinguyen@altera.com>

Thanks,
Dinh
> (+cc Lars-Peter Clausen, Thierry Reding)
> 
> According to the comment of devm_ioremap_resource(), 
> 'devm_ioremap_resource()' ioremaps it either as cacheable or
> as non-cacheable memory depending on the resource's flags
> Thus, devm_ioremap_nocache() will be called automatically.
> 
> ./lib/devres.c
> void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res)
> {
> 	....
> 
> 	if (res->flags & IORESOURCE_CACHEABLE)
> 		dest_ptr = devm_ioremap(dev, res->start, size);
> 	else
> 		dest_ptr = devm_ioremap_nocache(dev, res->start, size);
> 
> Best regards,
> Jingoo Han