Description of problem:
When booting rhel from serial console with encrypted home partition, plymouth provides password prompt, but I'm unable to unlock the partition. 
Kernel cmd entry is 'console=tty0 console=ttyS0,115200'. 
When booting w/o local console only with 'console=ttyS0' I'm able to enter the password and unlock the partition.

Version-Release number of selected component (if applicable):
plymouth-0.8.3-23.el6

How reproducible:
100%

Steps to Reproduce:
1. Have some encrypted disk
2. boot with kernel cmd entry 'console=tty0 console=ttyS0,115200'
3. try to enter the password from serial console
  
Actual results:
cannot enter password from serial console

Expected results:
able to unlock the partition from serial console. 

Additional info:
It is a regression (introduced in rhel6.1) in functionality as It worked in rhel60 because plymouthd crashed with multiple console entries (bug 631924) and password prompt was handled by cryptsetup. It is similar case as bug 719569, therefor proposing as a blocker for rhel6.2.
Workaround is to disable plymouth - boot with 'rd_NO_PLYMOUTH'.