DISK_REPAIR_TIME = 1m , disk is automatically dropped only after 5m

We are testing the value for DISK_REPAIR_TIME. 

I have set DISK_REPAIR_TIME value to 1m (same result is for 2m) but disk automatic drop operation did not started after 1 min but after 5 min.. can you explain why?

SQL> alter diskgroup test offline disk TEST_0000

Wed Nov 29 13:20:51 2017 <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<-------offlined here, 

NOTE: DRTimer CD Create: for disk group 2 disks: 0

NOTE: process _user25218_+asm1 (25218) initiating offline of disk 0.3916016358 (TEST_0000) with mask 0x7e in group 2 (TEST) without client assisting

NOTE: initiating PST update: grp 2 (TEST), dsk = 0/0xe969aae6, mask = 0x6a, op = clear

Wed Nov 29 13:20:51 2017

GMON updating disk modes for group 2 at 92 for pid 27, osid 25218