+
+ /*
+ * We need this for PCI devices only (Cardbus, PCI, miniPCI)
+ * _and_ if on non-uniprocessor systems (Multiprocessor/HT).
+ * This means we use it for all AR5416 devices, and the few
+ * minor PCI AR9280 devices out there.
+ *
+ * Serialization is required because these devices do not handle
+ * well the case of two concurrent reads/writes due to the latency
+ * involved. During one read/write another read/write can be issued
+ * on another CPU while the previous read/write may still be working
+ * on our hardware, if we hit this case the hardware poops in a loop.
+ * We prevent this by serializing reads and writes.
+ *
+ * This issue is not present on PCI-Express devices or pre-AR5416
+ * devices (legacy, 802.11abg).
+ */
+ if (num_possible_cpus() > 1)
+ ah->ah_config.serialize_regmode = SER_REG_MODE_AUTO;