From 23f9485510c338476b9735d516c1d4aacb810d46 Mon Sep 17 00:00:00 2001 From: Alexander Sverdlin Date: Tue, 18 Nov 2025 09:35:48 +0100 Subject: [PATCH 1/2] counter: interrupt-cnt: Drop IRQF_NO_THREAD flag An IRQ handler can either be IRQF_NO_THREAD or acquire spinlock_t, as CONFIG_PROVE_RAW_LOCK_NESTING warns: ============================= [ BUG: Invalid wait context ] 6.18.0-rc1+git... #1 ----------------------------- some-user-space-process/1251 is trying to lock: (&counter->events_list_lock){....}-{3:3}, at: counter_push_event [counter] other info that might help us debug this: context-{2:2} no locks held by some-user-space-process/.... stack backtrace: CPU: 0 UID: 0 PID: 1251 Comm: some-user-space-process 6.18.0-rc1+git... #1 PREEMPT Call trace: show_stack (C) dump_stack_lvl dump_stack __lock_acquire lock_acquire _raw_spin_lock_irqsave counter_push_event [counter] interrupt_cnt_isr [interrupt_cnt] __handle_irq_event_percpu handle_irq_event handle_simple_irq handle_irq_desc generic_handle_domain_irq gpio_irq_handler handle_irq_desc generic_handle_domain_irq gic_handle_irq call_on_irq_stack do_interrupt_handler el0_interrupt __el0_irq_handler_common el0t_64_irq_handler el0t_64_irq ... and Sebastian correctly points out. Remove IRQF_NO_THREAD as an alternative to switching to raw_spinlock_t, because the latter would limit all potential nested locks to raw_spinlock_t only. Cc: Sebastian Andrzej Siewior Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20251117151314.xwLAZrWY@linutronix.de/ Fixes: a55ebd47f21f ("counter: add IRQ or GPIO based counter") Signed-off-by: Alexander Sverdlin Reviewed-by: Sebastian Andrzej Siewior Reviewed-by: Oleksij Rempel Link: https://lore.kernel.org/r/20251118083603.778626-1-alexander.sverdlin@siemens.com Signed-off-by: William Breathitt Gray --- drivers/counter/interrupt-cnt.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/counter/interrupt-cnt.c b/drivers/counter/interrupt-cnt.c index 6c0c1d2d7027..e6100b5fb082 100644 --- a/drivers/counter/interrupt-cnt.c +++ b/drivers/counter/interrupt-cnt.c @@ -229,8 +229,7 @@ static int interrupt_cnt_probe(struct platform_device *pdev) irq_set_status_flags(priv->irq, IRQ_NOAUTOEN); ret = devm_request_irq(dev, priv->irq, interrupt_cnt_isr, - IRQF_TRIGGER_RISING | IRQF_NO_THREAD, - dev_name(dev), counter); + IRQF_TRIGGER_RISING, dev_name(dev), counter); if (ret) return ret; From 9517d76dd160208b7a432301ce7bec8fc1ddc305 Mon Sep 17 00:00:00 2001 From: Haotian Zhang Date: Mon, 15 Dec 2025 10:01:14 +0800 Subject: [PATCH 2/2] counter: 104-quad-8: Fix incorrect return value in IRQ handler quad8_irq_handler() should return irqreturn_t enum values, but it directly returns negative errno codes from regmap operations on error. Return IRQ_NONE if the interrupt status cannot be read. If clearing the interrupt fails, return IRQ_HANDLED to prevent the kernel from disabling the IRQ line due to a spurious interrupt storm. Also, log these regmap failures with dev_WARN_ONCE. Fixes: 98ffe0252911 ("counter: 104-quad-8: Migrate to the regmap API") Suggested-by: Andy Shevchenko Signed-off-by: Haotian Zhang Link: https://lore.kernel.org/r/20251215020114.1913-1-vulab@iscas.ac.cn Cc: stable@vger.kernel.org Signed-off-by: William Breathitt Gray --- drivers/counter/104-quad-8.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/drivers/counter/104-quad-8.c b/drivers/counter/104-quad-8.c index ce81fc4e1ae7..573b2fe93253 100644 --- a/drivers/counter/104-quad-8.c +++ b/drivers/counter/104-quad-8.c @@ -1192,6 +1192,7 @@ static irqreturn_t quad8_irq_handler(int irq, void *private) { struct counter_device *counter = private; struct quad8 *const priv = counter_priv(counter); + struct device *dev = counter->parent; unsigned int status; unsigned long irq_status; unsigned long channel; @@ -1200,8 +1201,11 @@ static irqreturn_t quad8_irq_handler(int irq, void *private) int ret; ret = regmap_read(priv->map, QUAD8_INTERRUPT_STATUS, &status); - if (ret) - return ret; + if (ret) { + dev_WARN_ONCE(dev, true, + "Attempt to read Interrupt Status Register failed: %d\n", ret); + return IRQ_NONE; + } if (!status) return IRQ_NONE; @@ -1223,8 +1227,9 @@ static irqreturn_t quad8_irq_handler(int irq, void *private) break; default: /* should never reach this path */ - WARN_ONCE(true, "invalid interrupt trigger function %u configured for channel %lu\n", - flg_pins, channel); + dev_WARN_ONCE(dev, true, + "invalid interrupt trigger function %u configured for channel %lu\n", + flg_pins, channel); continue; } @@ -1232,8 +1237,11 @@ static irqreturn_t quad8_irq_handler(int irq, void *private) } ret = regmap_write(priv->map, QUAD8_CHANNEL_OPERATION, CLEAR_PENDING_INTERRUPTS); - if (ret) - return ret; + if (ret) { + dev_WARN_ONCE(dev, true, + "Attempt to clear pending interrupts by writing to Channel Operation Register failed: %d\n", ret); + return IRQ_HANDLED; + } return IRQ_HANDLED; }