RFC: MPC5200 PSC AC97 driver

Matt Sealey matt at genesi-usa.com
Fri Apr 18 01:43:27 EST 2008


Juergen Beisert wrote:
> On Thursday 17 April 2008 17:10, Matt Sealey wrote:
>> Juergen Beisert wrote:
>>> Hi,
>>> +	/* the fifo starts right after psc ends */
>>> +	priv->fifo = (struct mpc52xx_psc_fifo*)&priv->psc[1];	/* FIXME */
>> Wouldn't
>>
>> 	priv->fifo = (struct mpc52xx_psc_fifo*) (priv->psc + sizeof(struct
>> mpc52xx_psc));
>>
>> Be a little less obtuse use of C?
> 
> "priv->psc" is of type "struct mpc52xx_ac97_priv*". If I add 0x58 to it, 
> wouldn't I add 0x58 times the size of "struct mpc52xx_ac97_priv"?

I always got a result of MBAR+PSC_OFFSET(n)+0x58 out of it as I expected.

priv->psc is of type struct mpc52xx_psc * which means it's just pointer
arithmetic. If you add a value to it (not increment or so as if it's
an array) then it just adds the value, no?

-- 
Matt Sealey <matt at genesi-usa.com>
Genesi, Manager, Developer Relations



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