+ /* do we need to poke the hardware? */
+ if (!(r ^ ro))
+ goto out;
+
+ /* ac97 engine is about to be disabled */
+ mutex_lock(&pscdata->lock);
+
+ /* disable AC97 device controller first... */
+ au_writel(r & ~PSC_AC97CFG_DE_ENABLE, AC97_CFG(pscdata));
+ au_sync();
+
+ /* ...wait for it... */
+ while (au_readl(AC97_STAT(pscdata)) & PSC_AC97STAT_DR)
+ asm volatile ("nop");
+
+ /* ...write config... */
+ au_writel(r, AC97_CFG(pscdata));
+ au_sync();
+
+ /* ...enable the AC97 controller again... */