Re: [EXT] Re: [PATCH] nvme: Add abrupt shutdown support

[Keith Busch]

On Mon, Jul 05, 2021 at 01:53:49PM +0200, Christoph Hellwig wrote:
> On Mon, Jul 05, 2021 at 11:15:51AM +0000, Shivamurthy Shastri (sshivamurthy) wrote:
> > For systems with passive electronic components to handle power-loss/battery-removal,
> > CC.SHN=10b will help to achieve safer shutdown with relatively lower power back-up 
> > requirements (at lower cost).
> > 
> > The module parameter gives flexibility to the host to decide shutdown type even during
> > boot failure. 
> 
> If you have a device that always prefers an abrupt please introduce a TP
> in the NVMe technical working group so that the hosts automatically
> do the right thing.  Requiring sysadmin intervention using a global
> kernel parameter is not the way to do this.

Is it the device that wants an abrupt shutdown or the platform? If the
platform's power is running on limited back-up supply, and could inform
the kernel's power management subsystem of this, then a driver could use
that to determine if the quick shutdown is appropriate.