I have received PSOD several times at diferent esxi hosts DL180 G6 (esxi 5.5 hp + applied all patches build: 1892794). There is a known issue with the hpsa driver that can cause PSODs, you should update to the latest scsi-hpsa 188.8.131.52 version.
~ # esxcli software vib list | grep hpsa scsi-hpsa 184.108.40.206-1OEM.5220.127.116.111820 Hewlett-Packard VMwareCertified 2014-05-01
Here is a link to the driver.
To force the install via the command line use:
#esxcli software vib update -v /tmp/scsi-hpsa-18.104.22.168-1OEM.522.214.171.1241820.x86_64.vib