SRB_FUNCTION_SHUTDOWN in SCSI miniport driver

I’m not receiving SRB_FUNCTION_SHUTDOWN calls within my SCSI miniport
driver, even through I’ve set the CachesData field of the
PORT_CONFIGURATION_INFORMATION block to 1.

I also have a upper port filter driver that calls
IoRegisterShutdownNotification() on every FiDO I create for each PDO that
I see in the IRP_MN_QUERY_DEVICE_RELATIONS list from the port driver. I
have my own routine for IRP_MJ_SHUTDOWN in the filter driver. This never
gets called either.

I have valid partitions on drives attached to my controller card, and
everything else works fine. I’m just trying to get a system shutdown
notification.

Any ideas? Thanks!

Greg de Valois