| Message ID | 20230327-tegra-pmic-reboot-v6-1-af44a4cd82e9@skidata.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | mfd: tps6586x: register restart handler | expand |
On 21:02-20230509, Benjamin Bara wrote: > From: Benjamin Bara <benjamin.bara@skidata.com> > > 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@vger.kernel.org # v5.2+ > Signed-off-by: Benjamin Bara <benjamin.bara@skidata.com> > --- > kernel/reboot.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/kernel/reboot.c b/kernel/reboot.c > index 3bba88c7ffc6..6ebef11c8876 100644 > --- a/kernel/reboot.c > +++ b/kernel/reboot.c > @@ -74,6 +74,7 @@ void __weak (*pm_power_off)(void); > void emergency_restart(void) > { > kmsg_dump(KMSG_DUMP_EMERG); > + system_state = SYSTEM_RESTART; > machine_emergency_restart(); > } > EXPORT_SYMBOL_GPL(emergency_restart); > > -- > 2.34.1 > Tested-by: Nishanth Menon <nm@ti.com> This in addition to a deeper bug in our driver seems to have helped resolve a report we had been looking at. Tested on beagleplay platform https://lore.kernel.org/all/ZGeHMjlnob2GFyHF@francesco-nb.int.toradex.com/
On 15:21-20230615, Francesco Dolcini wrote: > > > > > > -- > > > 2.34.1 > > > > > > > Tested-by: Nishanth Menon <nm@ti.com> > > > > This in addition to a deeper bug in our driver seems to have helped > > resolve a report we had been looking at. Tested on beagleplay platform > > > > https://lore.kernel.org/all/ZGeHMjlnob2GFyHF@francesco-nb.int.toradex.com/ > > Is this patch going to fix the RCU warning I reported on that email or > it is just part of a more complex solution?
diff --git a/kernel/reboot.c b/kernel/reboot.c index 3bba88c7ffc6..6ebef11c8876 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -74,6 +74,7 @@ void __weak (*pm_power_off)(void); void emergency_restart(void) { kmsg_dump(KMSG_DUMP_EMERG); + system_state = SYSTEM_RESTART; machine_emergency_restart(); } EXPORT_SYMBOL_GPL(emergency_restart);