Check for frozen PHB if register read returns all 1s

drivers/dahdi/opvxa24xx/private.c

@@ -127,6 +127,13 @@ unsigned int __opvx_a24xx_getcreg(struct a24xx_dev *wc, unsigned int offset, uns
 	//printk("reding offset %d, reg %d at %d\n", offset, reg, offset + (reg<<2));
 	volatile unsigned int *p = (unsigned int*)(wc->mem32 + offset + (reg<<2));
 
+#ifdef CONFIG_EEH
+	if (unlikely((*p) == ~((unsigned int)0))) {
+		struct eeh_dev *eehdev = pci_dev_to_eeh_dev(wc->dev);
+		eeh_dev_check_failure(eehdev);
+	}
+#endif
+
 	return (*p);
 }