From: Joshua Kinard <kumba@xxxxxxxxxx> Date: Sat, 17 Dec 2011 19:56:29 -0500 > +/* Maximum number of multicast addresses to filter (vs. Rx-all-multicast). > + * MACE Ethernet uses a 64 element hash table based on the Ethernet CRC. > + */ > +static int multicast_filter_limit = 32; > + > + Unnecessary empty line, only one is sufficient. I also don't see a reason to even define this value. If it's a constant then use a const type. > + /* Multicast filter. */ > + unsigned long mcast_filter; > + ... > + priv->mcast_filter = 0xffffffffffffffffUL; You're assuming that unsigned long is 64-bits here. You need to use a type which matches your expections regardless of the architecture that the code is built on. > + netdev_for_each_mc_addr(ha, dev) > + set_bit((ether_crc(ETH_ALEN, ha->addr) >> 26), > + (volatile long unsigned int *)&priv->mcast_filter); This makes an assumption not only about the size of the "unsigned long" type, but also of the endianness of the architecture this runs on. Please recode this to remove both assumptions.