[PATCH 5.4 51/66] spmi: pmic-arb: Set lockdep class for hierarchical irq domains

From: Greg Kroah-Hartman
Date: Tue Feb 18 2020 - 14:59:54 EST


From: Stephen Boyd <swboyd@xxxxxxxxxxxx>

commit 2d5a2f913b658a7ae984773a63318ed4daadf4af upstream.

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>
Link: https://lore.kernel.org/r/20200121183748.68662-1-swboyd@xxxxxxxxxxxx
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/spmi/spmi-pmic-arb.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/drivers/spmi/spmi-pmic-arb.c
+++ b/drivers/spmi/spmi-pmic-arb.c
@@ -731,6 +731,7 @@ static int qpnpint_irq_domain_translate(
return 0;
}

+static struct lock_class_key qpnpint_irq_lock_class, qpnpint_irq_request_class;

static void qpnpint_irq_domain_map(struct spmi_pmic_arb *pmic_arb,
struct irq_domain *domain, unsigned int virq,
@@ -746,6 +747,9 @@ static void qpnpint_irq_domain_map(struc
else
handler = handle_level_irq;

+
+ irq_set_lockdep_class(virq, &qpnpint_irq_lock_class,
+ &qpnpint_irq_request_class);
irq_domain_set_info(domain, virq, hwirq, &pmic_arb_irqchip, pmic_arb,
handler, NULL, NULL);
}