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

[Marc Kleine-Budde <mkl@pengutronix.de>]

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On 04/27/2011 03:18 PM, Subhasish Ghosh wrote:
> 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.

Incrementing a u32 pointer will result in increasing the address by 4
bytes. Incrementing a void pointer will result in increasing the address
by just one byte. (Pointer arithmetic on void * is a gnu extension but
IMHO a pretty nice one, though)

regards, Marc

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