cxgbe(4) crash on hw.cxgbe.largest_rx_cluster set

Upgraded 12 beta 2.1 -> RC1, and system promptly unable to boot.

It hits a kernel panic at the same point each time, although slightly different messages. Seems to perhaps be related to the cxgbe (Chelsio T540-CR) driver, according to panic dump?

I tried rebooting several times, it's consistent.

I also tried single user+verbose modes - it rebooted abruptly midway through boot without any messaages or warning.

Finally I had to boot via the beta 2.1 boot environment, and it had no problem at all with that.

Attached files:

• 4 x reboot serial console captures
• 1 x debug file via beta 2.1 but includes apparently the latest textdumps from today, under RC1