Re: [PATCH 4/8] drivers-edac-add Cell MC driver

[Andrew Morton <akpm@linux-foundation.org>]

On Fri, 19 Oct 2007 13:17:43 -0600
dougthompson@xmission.com wrote:

> +	/* The procedure for clearing FIR bits is a bit ... weird */
> +	if (clear) {
> +		fir &= ~(CBE_MIC_FIR_ECC_ERR_MASK | CBE_MIC_FIR_ECC_SET_MASK);
> +		fir |= CBE_MIC_FIR_ECC_RESET_MASK;
> +		fir &= ~clear;
> +		out_be64(&priv->regs->mic_fir, fir);
> +		(void)in_be64(&priv->regs->mic_fir);

The (void) cast isn't particularly popular practice.  Did you find that it
actually does anything useful?

> +
> +		mb();	/* sync up */

What's this here for?  It could do with a more usful comment.

If it's trying to perform some synchronisation of device register access
then I suspect it didn't work.  Or maybe it happens to work because of how
ppc implements mb(), in which case a direct use of the appropriate ppc
primitive might be clearer.

> +#ifdef DEBUG
> +		fir = in_be64(&priv->regs->mic_fir);
> +		dev_dbg(mci->dev, "fir clear  : 0x%016lx\n", fir);
> +#endif
> +	}