On Tue, Jan 21, 2020 at 7:37 PM Stephen Boyd <swboyd@xxxxxxxxxxxx> wrote:
> I see the following lockdep splat in the qcom pinctrl driver when
> attempting to suspend the device.
>
> WARNING: possible recursive locking detected
> 5.4.11 #3 Tainted: G W
> --------------------------------------------
> cat/3074 is trying to acquire lock:
> ffffff81f49804c0 (&irq_desc_lock_class){-.-.}, at: __irq_get_desc_lock+0x64/0x94
>
> but task is already holding lock:
> ffffff81f1cc10c0 (&irq_desc_lock_class){-.-.}, at: __irq_get_desc_lock+0x64/0x94
>
> other info that might help us debug this:
> Possible unsafe locking scenario:
>
> CPU0
> ----
> lock(&irq_desc_lock_class);
> lock(&irq_desc_lock_class);
>
> *** DEADLOCK ***
>
> May be due to missing lock nesting notation
>
> 6 locks held by cat/3074:
> #0: ffffff81f01d9420 (sb_writers#7){.+.+}, at: vfs_write+0xd0/0x1a4
> #1: ffffff81bd7d2080 (&of->mutex){+.+.}, at: kernfs_fop_write+0x12c/0x1fc
> #2: ffffff81f4c322f0 (kn->count#337){.+.+}, at: kernfs_fop_write+0x134/0x1fc
> #3: ffffffe411a41d60 (system_transition_mutex){+.+.}, at: pm_suspend+0x108/0x348
> #4: ffffff81f1c5e970 (&dev->mutex){....}, at: __device_suspend+0x168/0x41c
> #5: ffffff81f1cc10c0 (&irq_desc_lock_class){-.-.}, at: __irq_get_desc_lock+0x64/0x94
>
> stack backtrace:
> CPU: 5 PID: 3074 Comm: cat Tainted: G W 5.4.11 #3
> Hardware name: Google Cheza (rev3+) (DT)
> Call trace:
> dump_backtrace+0x0/0x174
> show_stack+0x20/0x2c
> dump_stack+0xc8/0x124
> __lock_acquire+0x460/0x2388
> lock_acquire+0x1cc/0x210
> _raw_spin_lock_irqsave+0x64/0x80
> __irq_get_desc_lock+0x64/0x94
> irq_set_irq_wake+0x40/0x144
> qpnpint_irq_set_wake+0x28/0x34
> set_irq_wake_real+0x40/0x5c
> irq_set_irq_wake+0x70/0x144
> pm8941_pwrkey_suspend+0x34/0x44
> platform_pm_suspend+0x34/0x60
> dpm_run_callback+0x64/0xcc
> __device_suspend+0x310/0x41c
> dpm_suspend+0xf8/0x298
> dpm_suspend_start+0x84/0xb4
> suspend_devices_and_enter+0xbc/0x620
> pm_suspend+0x210/0x348
> state_store+0xb0/0x108
> kobj_attr_store+0x14/0x24
> sysfs_kf_write+0x4c/0x64
> kernfs_fop_write+0x15c/0x1fc
> __vfs_write+0x54/0x18c
> vfs_write+0xe4/0x1a4
> ksys_write+0x7c/0xe4
> __arm64_sys_write+0x20/0x2c
> el0_svc_common+0xa8/0x160
> el0_svc_handler+0x7c/0x98
> el0_svc+0x8/0xc
>
> Set a lockdep class when we map the irq so that irq_set_wake() doesn't
> warn about a lockdep bug that doesn't exist.
>
> Fixes: 12a9eeaebba3 ("spmi: pmic-arb: convert to v2 irq interfaces to support hierarchical IRQ chips")
> Cc: Douglas Anderson <dianders@xxxxxxxxxxxx>
> Cc: Brian Masney <masneyb@xxxxxxxxxxxxx>
> Cc: Lina Iyer <ilina@xxxxxxxxxxxxxx>
> Cc: Maulik Shah <mkshah@xxxxxxxxxxxxxx>
> Cc: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> Signed-off-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
LGTM
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Yours,
Linus Walleij
