When the core detects permanent regulator hardware failure or imminent
power failure of a critical supply, it will call hw_protection_shutdown in
an attempt to do a limited orderly shutdown followed by powering off the
system.
This doesn't work out well for many unattended embedded systems that don't
have support for shutdown and that power on automatically when power is
supplied:
- A brief power cycle gets detected by the driver
- The kernel powers down the system and SoC goes into shutdown mode
- Power is restored
- The system remains oblivious to the restored power
- System needs to be manually power cycled for a duration long enough
to drain the capacitors
Allow users to fix this by calling the newly introduced
hw_protection_trigger() instead: This way the hw_protection commandline or
sysfs parameter is used to dictate the policy of dealing with the
regulator fault.
Link: https://lkml.kernel.org/r/20250217-hw_protection-reboot-v3-8-e1c09b090c0c@pengutronix.de
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
Reviewed-by: Matti Vaittinen <mazziesaccount@gmail.com>
Cc: Benson Leung <bleung@chromium.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Fabio Estevam <festevam@denx.de>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Lukasz Luba <lukasz.luba@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Matteo Croce <teknoraver@meta.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Rob Herring (Arm) <robh@kernel.org>
Cc: Rui Zhang <rui.zhang@intel.com>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The regulator IRQ helper requires caller to provide pointer to IRQ name
which is kept in memory by caller. All other data passed to the helper
in the regulator_irq_desc structure is copied. This can cause some
confusion and unnecessary complexity.
Make the regulator_irq_helper() to copy also the provided IRQ name
information so caller can discard the name after the call to
regulator_irq_helper() completes.
Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Link: https://msgid.link/r/ZhJMuUYwaZbBXFGP@drtxq0yyyyyyyyyyyyydy-3.rev.dnainternet.fi
Signed-off-by: Mark Brown <broonie@kernel.org>
The helper to send IRQ notification for regulator errors had still
old description mentioning calling BUG() as a last resort when
error status reading has kept failing for more times than a given
threshold.
The impementation calling BUG() did never end-up in-tree but was
replaced by hopefully more sophisticated handler trying to power-off
the system.
Fix the documentation to reflect actual behaviour.
Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Link: https://lore.kernel.org/r/20210823075651.GA3717293@localhost.localdomain
Signed-off-by: Mark Brown <broonie@kernel.org>
