Re: [PATCH 3/3] arm64: dts: qcom: qcm2290: Hook up MPM

From: Marek Szyprowski

Date: Thu Jul 16 2026 - 04:40:27 EST

On 15.07.2026 14:37, Maulik Shah (mkshah) wrote:
> On 7/15/2026 11:44 AM, Marek Szyprowski wrote:
>> On 14.07.2026 15:29, Maulik Shah (mkshah) wrote:
>>> On 7/14/2026 6:34 PM, Ulf Hansson wrote:
>>>> On Thu, Jul 9, 2026 at 1:41 PM Marek Szyprowski
>>>> <m.szyprowski@xxxxxxxxxxx> wrote:
>>> [...]
>>>
>>>> Without detailed HW expertise (still learning about the UnoQ), it
>>>> looks to me that the HW may have been modelled upside down.
>>>>
>>>> The power-domain-cpu-cluster should probably *not* be the consumer of
>>>> the mpm, but rather the opposite. This is how qcom,rpmh-rsc works, for
>>>> example.
>>> Agree, There is a series [1] sent out to fix modeling similar to how rpmh-rsc works.
>>>
>>> [1] https://lore.kernel.org/lkml/20260713-b4-shikra_lpm_addition-v1-0-3d858df2cbbf@xxxxxxxxxxxxxxxx/
>> Indeed that series fixes the modelling issue, but it doesn't change much
>> from the spinlock vs. raw_spinlock perspective. There is still the
>> 'invalid wait context' issue there, because mbox API cannot be properly
>> called from cpu_pm_notifier (which use raw_notifier internally):
> Okay, i see why series [1] did not help for agatti due to fallback on CPU PM notification.
>
> On PREEMPT_RT kernel, GENPD is marked as always RPM always on,
> So MPM driver never get the .power_off callback it registered for and hence MPM irqchip won't invoke mbox_() APIs.
>
> from drivers/cpuidle/cpuidle-psci-domain.c,
>
> /*
> * On a PREEMPT_RT based configuration the domain idle states are
> * supported, but only during system-wide suspend.
> */
> if (IS_ENABLED(CONFIG_PREEMPT_RT))
> pd->flags |= GENPD_FLAG_RPM_ALWAYS_ON;
>
> The series [1] fallbacks to CPU_PM based notification if "power-domains" property is not added.
> having a power-domains property would have avoided the BUG for agatti on RT kernel.
>
> Agatti device tree change in the series [2] only removed power-domain-cells# but did not add power-domains = <&cluster_pd>;
> with the reason that qrb2210-rb1.dts had deleted "cluster_pd" however qrb2210-arduino-imola.dts still have it.
>
> so below change on top of [1] series would avoid the BUG from mpm_cpu_pm_callback().

This change moves the 'invalid wait context' warning from boot time to system suspend/resume path (although the system suspend/resume is and was broken on UnoQ at least with current next with and without the patchset from this thread):

root@target:~# time rtcwake -s5 -mmem
rtcwake: assuming RTC uses UTC ...
rtcwake: wakeup from "mem" using /dev/rtc0 at Thu Jan 1 00:03:11 1970
[ 146.369961] PM: suspend entry (deep)
[ 146.400523] Filesystems sync: 0.021 seconds
[ 146.441862] Freezing user space processes
[ 146.457851] Freezing user space processes completed (elapsed 0.011 seconds)
[ 146.465487] OOM killer disabled.
[ 146.468880] Freezing remaining freezable tasks
[ 146.478491] Freezing remaining freezable tasks completed (elapsed 0.004 seconds)
[ 146.486154] printk: Suspending console(s) (use no_console_suspend to debug)
[ 146.782051] dwc3-qcom-legacy 4ef8800.usb: port-1 HS-PHY not in L2
[ 146.859869] Disabling non-boot CPUs ...
[ 146.912706] IRQ95: set affinity failed(-22).
[ 146.912818] IRQ96: set affinity failed(-22).
[ 146.913155] IRQ150: set affinity failed(-22).
[ 146.918079] psci: CPU3 killed (polled 0 ms)
[ 146.948827] IRQ95: set affinity failed(-22).
[ 146.948896] IRQ96: set affinity failed(-22).
[ 146.949230] IRQ150: set affinity failed(-22).
[ 146.949685] psci: CPU2 killed (polled 0 ms)
[ 146.982811] IRQ95: set affinity failed(-22).
[ 146.982878] IRQ96: set affinity failed(-22).
[ 146.983213] IRQ150: set affinity failed(-22).
[ 146.984074] psci: CPU1 killed (polled 4 ms)
[ 146.990260]
[ 146.990295] =============================
[ 146.990299] [ BUG: Invalid wait context ]
[ 146.990308] 7.2.0-rc3-next-20260714+ #16842 Not tainted
[ 146.990318] -----------------------------
[ 146.990321] rtcwake/673 is trying to lock:
[ 146.990332] ffff0000008ac408 (&chan->lock){....}-{3:3}, at: mbox_send_message+0x3c/0x15c
[ 146.990391] other info that might help us debug this:
[ 146.990395] context-{5:5}
[ 146.990399] locks held by rtcwake/673: 6, last CPU#0:
[ 146.990404] #0: ffff0000099a2438 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0x2dc/0x370
[ 146.990432] #1: ffff000016009280 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_fop_write_iter+0xf0/0x1c0
[ 146.990462] #2: ffff000000995f28 (kn->active#97){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x100/0x1c0
[ 146.990481] #3: ffffd083befc03f0 (system_transition_mutex){+.+.}-{4:4}, at: pm_suspend+0x200/0x370
[ 146.990507] #4: ffff00000036af50 (&genpd->raw_slock){....}-{2:2}, at: genpd_lock_raw_spin+0x1c/0x30
[ 146.990534] #5: ffff00000036a750 (&genpd->raw_slock/1){....}-{2:2}, at: genpd_lock_nested_raw_spin+0x1c/0x30
[ 146.990557] stack backtrace:
[ 146.990568] CPU: 0 UID: 0 PID: 673 Comm: rtcwake Not tainted 7.2.0-rc3-next-20260714+ #16842 PREEMPT
[ 146.990576] Hardware name: Arduino UnoQ (DT)
[ 146.990582] Call trace:
[ 146.990587] show_stack+0x18/0x24 (C)
[ 146.990600] dump_stack_lvl+0x8c/0xcc
[ 146.990615] dump_stack+0x18/0x24
[ 146.990622] __lock_acquire+0x928/0x1f90
[ 146.990635] lock_acquire+0x2b8/0x3ec
[ 146.990642] _raw_spin_lock_irqsave+0x60/0x88
[ 146.990656] mbox_send_message+0x3c/0x15c
[ 146.990664] handle_rpm_notification+0x58/0x114
[ 146.990678] mpm_pd_power_cb+0x20/0x3c
[ 146.990686] notifier_call_chain+0xa0/0x234
[ 146.990701] raw_notifier_call_chain_robust+0x48/0xa8
[ 146.990708] _genpd_power_off+0x38/0x154
[ 146.990714] genpd_sync_power_off.part.0+0xa4/0x240
[ 146.990723] genpd_sync_power_off.part.0+0x224/0x240
[ 146.990729] genpd_switch_state+0x130/0x138
[ 146.990739] dev_pm_genpd_suspend+0x14/0x20
[ 146.990747] psci_idle_syscore_switch+0x118/0x120
[ 146.990759] psci_idle_syscore_suspend+0x14/0x24
[ 146.990765] syscore_suspend+0x74/0x1b8
[ 146.990778] suspend_devices_and_enter+0x1f4/0x7fc
[ 146.990786] pm_suspend+0x274/0x370
[ 146.990792] state_store+0x80/0x104
[ 146.990798] kobj_attr_store+0x18/0x2c
[ 146.990809] sysfs_kf_write+0x50/0x7c
[ 146.990816] kernfs_fop_write_iter+0x130/0x1c0
[ 146.990822] vfs_write+0x240/0x370
[ 146.990828] ksys_write+0x70/0x108
[ 146.990835] __arm64_sys_write+0x1c/0x28
[ 146.990841] invoke_syscall+0x54/0x10c
[ 146.990849] el0_svc_common.constprop.0+0x40/0xe0
[ 146.990856] do_el0_svc+0x1c/0x28
[ 146.990861] el0_svc+0x54/0x3a0
[ 146.990867] el0t_64_sync_handler+0xa0/0xe4
[ 146.990872] el0t_64_sync+0x198/0x19c
[ 146.991113] Enabling non-boot CPUs ...
[ 146.992161] Detected VIPT I-cache on CPU1
[ 146.992262] GICv3: CPU1: found redistributor 1 region 0:0x000000000f320000
[ 146.992407] CPU1: Booted secondary processor 0x0000000001 [0x51af8014]
[ 146.995104] CPU1 is up
[ 146.996182] Detected VIPT I-cache on CPU2
[ 146.996282] GICv3: CPU2: found redistributor 2 region 0:0x000000000f340000
[ 146.996425] CPU2: Booted secondary processor 0x0000000002 [0x51af8014]
[ 146.998746] CPU2 is up
[ 146.999673] Detected VIPT I-cache on CPU3
[ 146.999760] GICv3: CPU3: found redistributor 3 region 0:0x000000000f360000
[ 146.999893] CPU3: Booted secondary processor 0x0000000003 [0x51af8014]
[ 147.002366] CPU3 is up
[ 147.949024] OOM killer enabled.
[ 147.952218] Restarting tasks: Starting
[ 147.960927] Restarting tasks: Done
[ 147.964583] random: crng reseeded on system resumption
[ 147.976461] PM: suspend exit
rtcwake: write error

real    0m1.679s
user    0m0.000s
sys     0m0.688s

>
> --- a/arch/arm64/boot/dts/qcom/agatti.dtsi
> +++ b/arch/arm64/boot/dts/qcom/agatti.dtsi
> @@ -281,6 +281,7 @@ mpm: interrupt-controller {
> interrupt-controller;
> #interrupt-cells = <2>;
> interrupt-parent = <&intc>;
> + power-domains = <&cluster_pd>;
> qcom,mpm-pin-count = <96>;
> qcom,mpm-pin-map = <2 275>, /* TSENS0 uplow */
> <5 296>, /* Soundwire master_irq */
> diff --git a/arch/arm64/boot/dts/qcom/qrb2210-rb1.dts b/arch/arm64/boot/dts/qcom/qrb2210-rb1.dts
> index bf6fb12ad990..7dc2cade0a7f 100644
> --- a/arch/arm64/boot/dts/qcom/qrb2210-rb1.dts
> +++ b/arch/arm64/boot/dts/qcom/qrb2210-rb1.dts
> @@ -246,6 +246,10 @@ &cpu_pd3 {
>
> /delete-node/ &cluster_pd;
>
> +&mpm {
> + /delete-property/ power-domains;
> +};
> +
>
> [2] https://lore.kernel.org/linux-arm-msm/20260713-b4-shikra_lpm_addition-v1-0-3d858df2cbbf@xxxxxxxxxxxxxxxx/T/#m5bbdb535424c38209cc08e6afeae5e3aac9f6cc0
>
> Thanks,
> Maulik
>
>> =============================
>> [ BUG: Invalid wait context ]
>> 7.2.0-rc3-next-20260714+ #16842 Not tainted
>> -----------------------------
>> swapper/3/0 is trying to lock:
>> ffff0000008ac408 (&chan->lock){....}-{3:3}, at: mbox_send_message+0x3c/0x15c
>> other info that might help us debug this:
>> context-{5:5}
>> locks held by swapper/3/0: 1, last CPU#3:
>> #0: ffffd99263a61228 (cpu_pm_notifier.lock){....}-{2:2}, at: cpu_pm_enter+0x28/0x78
>> stack backtrace:
>> CPU: 3 UID: 0 PID: 0 Comm: swapper/3 Not tainted 7.2.0-rc3-next-20260714+ #16842 PREEMPT
>> Hardware name: Arduino UnoQ (DT)
>> Call trace:
>> show_stack+0x18/0x24 (C)
>> dump_stack_lvl+0x8c/0xcc
>> dump_stack+0x18/0x24
>> __lock_acquire+0x928/0x1f90
>> lock_acquire+0x2b8/0x3ec
>> _raw_spin_lock_irqsave+0x60/0x88
>> mbox_send_message+0x3c/0x15c
>> handle_rpm_notification+0x58/0x114
>> mpm_cpu_pm_callback+0x9c/0xdc
>> notifier_call_chain+0xa0/0x234
>> raw_notifier_call_chain_robust+0x48/0xa8
>> cpu_pm_enter+0x40/0x78
>> __psci_enter_domain_idle_state.isra.0+0x48/0x470
>> psci_enter_domain_idle_state+0x18/0x24
>> cpuidle_enter_state+0xbc/0x428
>> cpuidle_enter+0x38/0x50
>> do_idle+0x158/0x324
>> cpu_startup_entry+0x38/0x3c
>> secondary_start_kernel+0x138/0x158
>> __secondary_switched+0xc0/0xc4
>>
>> Best regards
>
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland