Ethernet driver DPC reinit messages from Yosemite kernel

I have one Mac that is experiencing periods of sluggish wireless networking.

I am seeing system.log messages around these times of the following sort:

Jan 16 08:02:50 mac kernel[0]: ARPT: 139243.965792: wl0: 802.11 driver DPC, reinit reason[5], count[13]

Jan 16 08:22:08 mac kernel[0]: ARPT: 140402.354334: wl0: 802.11 driver reinitializing, total count of reinit's[196], @'wlc_dpc':466

The count[xx] are clearly counting up each time the message is logged but the rest of the meaning escapes me. I'm not seeing anything odd or different on other Mac that are close by and Wireless Diagnostics shows nothing amiss.

Are these Airport driver DPC reinit reasons (5 in this case) documented anywhere so I can know what I might need to address or change on that Mac?