[PATCH 5.15 214/297] kernel/reboot: emergency_restart: Set correct system_state

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5.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Benjamin Bara <benjamin.bara@xxxxxxxxxxx>

commit 60466c067927abbcaff299845abd4b7069963139 upstream.

As the emergency restart does not call kernel_restart_prepare(), the
system_state stays in SYSTEM_RUNNING.

Since bae1d3a05a8b, this hinders i2c_in_atomic_xfer_mode() from becoming
active, and therefore might lead to avoidable warnings in the restart
handlers, e.g.:

[   12.667612] WARNING: CPU: 1 PID: 1 at kernel/rcu/tree_plugin.h:318 rcu_note_context_switch+0x33c/0x6b0
[   12.676926] Voluntary context switch within RCU read-side critical section!
...
[   12.742376]  schedule_timeout from wait_for_completion_timeout+0x90/0x114
[   12.749179]  wait_for_completion_timeout from tegra_i2c_wait_completion+0x40/0x70
...
[   12.994527]  atomic_notifier_call_chain from machine_restart+0x34/0x58
[   13.001050]  machine_restart from panic+0x2a8/0x32c

Avoid these by setting the correct system_state.

Fixes: bae1d3a05a8b ("i2c: core: remove use of in_atomic()")
Cc: stable@xxxxxxxxxxxxxxx # v5.2+
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>
Tested-by: Nishanth Menon <nm@xxxxxx>
Signed-off-by: Benjamin Bara <benjamin.bara@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230327-tegra-pmic-reboot-v7-1-18699d5dcd76@xxxxxxxxxxx
Signed-off-by: Lee Jones <lee@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 kernel/reboot.c |    1 +
 1 file changed, 1 insertion(+)

--- a/kernel/reboot.c
+++ b/kernel/reboot.c
@@ -65,6 +65,7 @@ EXPORT_SYMBOL_GPL(pm_power_off_prepare);
 void emergency_restart(void)
 {
 	kmsg_dump(KMSG_DUMP_EMERG);
+	system_state = SYSTEM_RESTART;
 	machine_emergency_restart();
 }
 EXPORT_SYMBOL_GPL(emergency_restart);






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