MRSAS - Connected Sata port question

[John Fleming]

https://github.com/freebsd/freebsd/blob/master/sys/dev/mrsas/mrsas_cam.c#L359

ccb->cpi.base_transfer_speed = 150000;

What is that used for? I poked around /usr/src/sys and found multiple
WTF comments. The reason I ask is i have Samsung EVO 860s plugged into
a Dell R720 (via LSI 9361 which is where mrsas comes from (also have
mfi disabled)) and seeing da0 speed of 150.000MB/sec in dmesg output
is a bit strange. I hacked the source and moved it to 600 and sure
enough it now reports 600MB/sec on boot up. I haven't benchmarked old
vs new yet because the system in question can't be rebooted for a
while.