Hi! The Tegra20 requires an enabled VDE power domain during startup. As the VDE is currently not used, it is disabled during runtime. Since [1], there is a workaround for the "normal restart path" which enables the VDE before doing PMC's warm reboot. This workaround is not executed in the "emergency restart path", leading to a hang-up during start. This series implements and registers a new pmic-based restart handler for boards with tps6586x. This cold reboot ensures that the VDE power domain is enabled on tegra20-based boards. During panic(), preemption is disabled. This should be correctly detected by i2c_in_atomic_xfer_mode() to use atomic i2c xfer in this late stage. This avoids warnings regarding "Voluntary context switch within RCU". [1] 8f0c714ad9be1ef774c98e8819a7a571451cb019 v2: https://lore.kernel.org/all/20230320220345.1463687-1-bbara93@xxxxxxxxx/ system_state: https://lore.kernel.org/all/20230320213230.1459532-1-bbara93@xxxxxxxxx/ v1: https://lore.kernel.org/all/20230316164703.1157813-1-bbara93@xxxxxxxxx/ v3: - bring system_state back in this series - do atomic i2c xfer if not preemptible (as suggested by Dmitry) - fix style issues mentioned by Dmitry - add cc stable as suggested by Dmitry - add explanation why this is needed for Jon v2: - use devm-based restart handler - convert the existing power_off handler to a devm-based handler - handle system_state in extra series --- Benjamin Bara (4): kernel/reboot: emergency_restart: set correct system_state i2c: core: run atomic i2c xfer when !preemptible mfd: tps6586x: use devm-based power off handler mfd: tps6586x: register restart handler drivers/i2c/i2c-core.h | 2 +- drivers/mfd/tps6586x.c | 43 +++++++++++++++++++++++++++++++++++-------- kernel/reboot.c | 1 + 3 files changed, 37 insertions(+), 9 deletions(-) --- base-commit: 197b6b60ae7bc51dd0814953c562833143b292aa change-id: 20230327-tegra-pmic-reboot-4175ff814a4b Best regards, -- Benjamin Bara <benjamin.bara@xxxxxxxxxxx>
