[BUG] 6.16-rc7: lockdep failure with max77620-gpio/max77686-rtc

["Russell King (Oracle)" <linux@armlinux.org.uk>]

Hi,

First, I'm not sure who is responsible for the max77620-gpio driver
(it's not in MAINTAINERS) but this bug points towards a problem with
one or other of these drivers.

Here is /proc/interrupts which may help debug this:

           CPU0       CPU1       CPU2       CPU3       CPU4       CPU5
 94:          1          0          0          0          0          0 max77620-
top   4 Edge      max77686-rtc
 95:          1          0          0          0          0          0 max77686-rtc   1 Edge      rtc-alarm1

While running 6.16-rc7 on the Jetson Xavier NX platform, upon suspend,
I receive the following lockdep splat. I've added some instrumentation
into irq_set_irq_wake() which appears twice in the calltrace to print
the IRQ number and the "on" parameter to locate which interrupts are
involved in this splat. This splat is 100% reproducable.

[   46.721367] irq_set_irq_wake: irq=95 on=1
[   46.722067] irq_set_irq_wake: irq=94 on=1
[   46.722181] ============================================
[   46.722578] WARNING: possible recursive locking detected
[   46.722852] 6.16.0-rc7-net-next+ #432 Not tainted
[   46.722965] --------------------------------------------
[   46.723127] rtcwake/3984 is trying to acquire lock:
[   46.723235] ffff0000813b2c68 (&d->lock){+.+.}-{4:4}, at: regmap_irq_lock+0x18/0x24
[   46.723452]
               but task is already holding lock:
[   46.723556] ffff00008504dc68 (&d->lock){+.+.}-{4:4}, at: regmap_irq_lock+0x18/0x24
[   46.723780]
               other info that might help us debug this:
[   46.723903]  Possible unsafe locking scenario:

[   46.724015]        CPU0
[   46.724067]        ----
[   46.724119]   lock(&d->lock);
[   46.724212]   lock(&d->lock);
[   46.724282]
                *** DEADLOCK ***

[   46.724348]  May be due to missing lock nesting notation

[   46.724492] 6 locks held by rtcwake/3984:
[   46.724576]  #0: ffff0000825693f8 (sb_writers#3){.+.+}-{0:0}, at: vfs_write+0x184/0x350
[   46.724902]  #1: ffff00008fd7fa88 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x104/0x1c8
[   46.725258]  #2: ffff000080a64588 (kn->active#87){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x10c/0x1c8
[   46.725609]  #3: ffff8000815d4fb8 (system_transition_mutex){+.+.}-{4:4}, at: pm_suspend+0x220/0x300
[   46.725897]  #4: ffff00008500a8f8 (&dev->mutex){....}-{4:4}, at: device_suspend+0x1d8/0x630
[   46.726173]  #5: ffff00008504dc68 (&d->lock){+.+.}-{4:4}, at: regmap_irq_lock+0x18/0x24
[   46.732435]
               stack backtrace:
[   46.734019] CPU: 3 UID: 0 PID: 3984 Comm: rtcwake Not tainted 6.16.0-rc7-net-next+ #432 PREEMPT
[   46.734029] Hardware name: NVIDIA NVIDIA Jetson Xavier NX Developer Kit/Jetson, BIOS 6.0-37391689 08/28/2024
[   46.734033] Call trace:
[   46.734036]  show_stack+0x18/0x24 (C)
[   46.734070]  dump_stack_lvl+0x90/0xd0
[   46.734080]  dump_stack+0x18/0x24
[   46.734107]  print_deadlock_bug+0x260/0x350
[   46.734114]  __lock_acquire+0xf28/0x2088
[   46.734120]  lock_acquire+0x19c/0x33c
[   46.734126]  __mutex_lock+0x84/0x530
[   46.734135]  mutex_lock_nested+0x24/0x30
[   46.734155]  regmap_irq_lock+0x18/0x24
[   46.734161]  __irq_get_desc_lock+0x8c/0x9c
[   46.734170]  irq_set_irq_wake+0x5c/0x1ac	<== I guess IRQ 94
[   46.734176]  regmap_irq_sync_unlock+0x314/0x4f4
[   46.734182]  __irq_put_desc_unlock+0x48/0x4c
[   46.734190]  irq_set_irq_wake+0x88/0x1ac	<== I guess IRQ 95
[   46.734195]  max77686_rtc_suspend+0x34/0x74
[   46.734206]  platform_pm_suspend+0x2c/0x6c
[   46.734214]  dpm_run_callback+0xa4/0x218
[   46.734221]  device_suspend+0x200/0x630
[   46.734227]  dpm_suspend+0x17c/0x2d0
[   46.734233]  dpm_suspend_start+0x74/0x7c
[   46.734240]  suspend_devices_and_enter+0x104/0x618
[   46.734247]  pm_suspend+0x1b4/0x300
[   46.734254]  state_store+0x8c/0x110
[   46.734261]  kobj_attr_store+0x18/0x2c
[   46.734268]  sysfs_kf_write+0x50/0x7c
[   46.734275]  kernfs_fop_write_iter+0x134/0x1c8
[   46.734282]  vfs_write+0x24c/0x350
[   46.734289]  ksys_write+0x58/0xec
[   46.734295]  __arm64_sys_write+0x1c/0x28
[   46.734302]  invoke_syscall.constprop.0+0x50/0xe4
[   46.734311]  do_el0_svc+0x40/0xc8
[   46.734318]  el0_svc+0x44/0x148
[   46.734327]  el0t_64_sync_handler+0xc8/0xcc
[   46.734333]  el0t_64_sync+0x19c/0x1a0

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