These messages mostly due to the CPU being busy sometimes in the past. The error message :"soft watchdog expiration warning EPC" indicates that :
<Crit:Kern.Alert> MSM-A: CPU 0: Kernel thread was stuck for 2.10 seconds, jiffies: 1347292198
<Crit:Kern.Alert> MSM-A: CPU 0: soft watchdog expiration warning EPC 803f6e14(_spin_unlock_irqrestore+0x4
watchdog timer starts ticking for 120 seconds and then reboots the switch if it does not receive a particular health check message from the process. However from the logs, the watch dog received a health check message when the timer is at 2 seconds. So it cleared the timer.
In most of the cases their appearances are very rare and not frequent. Also no more crash or core dump being noticed So in this scenario we can mostly ignore them and continue monitoring further.