Every so often (at least hourly today) with 3.9.1-301.fc19, I see what seems to be a divide-by-zero in brcms_c_calc_frame_time(), called from brcms_c_compute_rtscts_dur().  This is on a mid-2012 Ivy Bridge MacBook Air, with a BRCM43224 chip.

Probably notable is that I have an _extremely_ marginal connection to the AP: if I move out of my bedroom, I can't even see it beaconing anymore, and I get quite frequent and long dropouts.  So this is probably quite pathological in terms of retry/etc behaviour.

As it's a hard panic, I don't have any saved OOPSes, but I hope you enjoy the attached picture, with all the quality of a five-year old phonecam, because it was taken with a five-year old phone.

Please let me know if there's anything more I can do: unfortunately I can't get the kernel source for any further debugging, since this connection is so bad and rarely lasts long enough before OOPSing to download much anything ...