You’ve enabled ASM Filter Drivers, migrated your existing disks, and then after you reboot you see this:

[oracle@oel6solo ~]$ asmcmd afd_lsdsk
--------------------------------------------------------------------------------
Label Filtering Path
================================================================================
DATA2 DISABLED /dev/sdc
DATA4 DISABLED /dev/sde
DATA3 DISABLED /dev/sdd
DATA1 DISABLED /dev/sdb

You check the ASM Filter Driver state and it says it is loaded and filtering:

[oracle@oel6solo ~]$ asmcmd afd_state
ASMCMD-9526: The AFD state is 'LOADED' and filtering is 'DEFAULT' on host 'oel6solo.comp-lab.sc'

There is one more step that much of the documenation is missing:

[oracle@oel6solo ~]$ $ORACLE_HOME/bin/asmcmd afd_filter -e

Now the ASM FD filtering will survive a reboot:

[oracle@oel6solo ~]$ asmcmd afd_lsdsk
--------------------------------------------------------------------------------
Label Filtering Path
================================================================================
DATA2 ENABLED /dev/sdc
DATA4 ENABLED /dev/sde
DATA3 ENABLED /dev/sdd
DATA1 ENABLED /dev/sdb