Re: [PATCH v4 01/11] mfd: add pruss mfd driver.

[Subhasish Ghosh]

My problem is, I am doing something like this:

s32 pruss_writel_multi(struct device *dev, u32 offset,
               u32 *pdatatowrite, u16 wordstowrite)
{
       struct pruss_priv *pruss = dev_get_drvdata(dev->parent);
       u32 __iomem *paddresstowrite;
       u16 i;

       paddresstowrite = pruss->ioaddr + offset;

       for (i = 0; i < wordstowrite; i++)
               iowrite32(*pdatatowrite++, paddresstowrite++);

       return 0;
}

So, if I make paddresstowrite as void, it will not work. 
The above implementation does not generate any sparse errors though.


> On Wed, Apr 27, 2011 at 09:29:59AM +0200, Marc Kleine-Budde wrote:
> > On 04/27/2011 08:39 AM, Subhasish Ghosh wrote:
> > > - Is it ok to have u32 etc for __iomem cookie ?
> >
> > no - "void __iomem *" is "void __iomem *"
>
> Actually, it is _provided_ you don't directly dereference it.  You can
> then do pointer arithmetic on it in the usual way - which is about the
> only valid thing to do with an __iomem pointer.  The voidness just acts
> as an additional check against direct dereferences of this.
>
> The important thing though is that the code passes sparse checks. 
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