From: Bartosz Golaszewski bgolaszewski@baylibre.com
[ Upstream commit 6eeb997ab5075e770a002c51351fa4ec2c6b5c39 ]
This driver may take a regular spinlock when a raw spinlock (irq_desc->lock) is already taken which results in the following lockdep splat:
============================= [ BUG: Invalid wait context ] 5.7.0-rc7 #1 Not tainted ----------------------------- swapper/0/0 is trying to lock: ffffff800303b798 (&chip_data->lock){....}-{3:3}, at: mtk_sysirq_set_type+0x48/0xc0 other info that might help us debug this: context-{5:5} 2 locks held by swapper/0/0: #0: ffffff800302ee68 (&desc->request_mutex){....}-{4:4}, at: __setup_irq+0xc4/0x8a0 #1: ffffff800302ecf0 (&irq_desc_lock_class){....}-{2:2}, at: __setup_irq+0xe4/0x8a0 stack backtrace: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.7.0-rc7 #1 Hardware name: Pumpkin MT8516 (DT) Call trace: dump_backtrace+0x0/0x180 show_stack+0x14/0x20 dump_stack+0xd0/0x118 __lock_acquire+0x8c8/0x2270 lock_acquire+0xf8/0x470 _raw_spin_lock_irqsave+0x50/0x78 mtk_sysirq_set_type+0x48/0xc0 __irq_set_trigger+0x58/0x170 __setup_irq+0x420/0x8a0 request_threaded_irq+0xd8/0x190 timer_of_init+0x1e8/0x2c4 mtk_gpt_init+0x5c/0x1dc timer_probe+0x74/0xf4 time_init+0x14/0x44 start_kernel+0x394/0x4f0
Replace the spinlock_t with raw_spinlock_t to avoid this warning.
Signed-off-by: Bartosz Golaszewski bgolaszewski@baylibre.com Signed-off-by: Marc Zyngier maz@kernel.org Link: https://lore.kernel.org/r/20200615074445.3579-1-brgl@bgdev.pl Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/irqchip/irq-mtk-sysirq.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/irqchip/irq-mtk-sysirq.c b/drivers/irqchip/irq-mtk-sysirq.c index 90aaf190157f7..42455f31b0611 100644 --- a/drivers/irqchip/irq-mtk-sysirq.c +++ b/drivers/irqchip/irq-mtk-sysirq.c @@ -23,7 +23,7 @@ #include <linux/spinlock.h>
struct mtk_sysirq_chip_data { - spinlock_t lock; + raw_spinlock_t lock; u32 nr_intpol_bases; void __iomem **intpol_bases; u32 *intpol_words; @@ -45,7 +45,7 @@ static int mtk_sysirq_set_type(struct irq_data *data, unsigned int type) reg_index = chip_data->which_word[hwirq]; offset = hwirq & 0x1f;
- spin_lock_irqsave(&chip_data->lock, flags); + raw_spin_lock_irqsave(&chip_data->lock, flags); value = readl_relaxed(base + reg_index * 4); if (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_EDGE_FALLING) { if (type == IRQ_TYPE_LEVEL_LOW) @@ -61,7 +61,7 @@ static int mtk_sysirq_set_type(struct irq_data *data, unsigned int type)
data = data->parent_data; ret = data->chip->irq_set_type(data, type); - spin_unlock_irqrestore(&chip_data->lock, flags); + raw_spin_unlock_irqrestore(&chip_data->lock, flags); return ret; }
@@ -220,7 +220,7 @@ static int __init mtk_sysirq_of_init(struct device_node *node, ret = -ENOMEM; goto out_free_which_word; } - spin_lock_init(&chip_data->lock); + raw_spin_lock_init(&chip_data->lock);
return 0;