[ofw] ***SPAM*** RE: System shutdown failure - living on the edge

[Fab Tillier]

> What suggestions might you provide to repair this situation such that
> the IBAL async threads are shutdown prior to passing the POWER IRP down
> to the HCA driver.

What used to happen before ibbus became a filter driver is that the HCA driver would treat powering off (moving out of D0) the same was as HCA removal.  At this point, it's your only/best bet.

Longer term, it would be great if the HCA driver kept state and restored what it could when it powers back up.  Much of the state can be restored - all resource can be re-allocated, all pending work requests can be completed, all completed CQEs can be reaped, etc.  What you can't restore are connections for RC and UD QPs, and for those the HCA driver could generate a QP fatal error, or flush all posted work requests.

This would require significant rework of the HCA driver, so it's not an easy fix, but it would allow for things to not have to be fully torn down/recreated.

-Fab