Re: [RFC PATCH v1 7/7] thermal: core: set Power State Change Reason before hw_protection_shutdown()

[Oleksij Rempel <o.rempel@pengutronix.de>]

On Fri, Jan 19, 2024 at 07:34:26PM +0100, Rafael J. Wysocki wrote:
> On Fri, Jan 19, 2024 at 2:25 PM Oleksij Rempel <o.rempel@pengutronix.de> wrote:
> >
> > Store the state change reason to some black box for later investigation.
> 
> Seriously?
> 
> What black box, where, how this is useful and who is going to use it,
> pretty please.

The 'black box' refers to a non-volatile memory (NVMEM) cell used by the
Power State Change Reasons (PSCR) framework. This cell stores reasons
for sudden power state changes, like voltage drops or over-temperature
events. This data is invaluable for post-mortem analysis to understand
system failures or abrupt shutdowns. It's particularly useful for
systems where PMICs or watchdogs cannot record such events. The data can
inform recovery routines in the bootloader or early kernel stages during
subsequent boots, enhancing system reliability and aiding in debugging
and diagnostics.

Regards,
Oleksij
-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |