[PATCH v13 02/13] irqchip/sifive-plic: Improve locking safety by using irqsave/irqrestore

Thomas Gleixner tglx at linutronix.de
Tue Feb 20 02:11:19 PST 2024


On Tue, Feb 20 2024 at 11:37, Anup Patel wrote:
> Now that PLIC driver is probed as a regular platform driver, the lock
> dependency validator complains about the safety of handler->enable_lock
> usage:
>
> [    0.956775]  Possible interrupt unsafe locking scenario:
>
> [    0.956998]        CPU0                    CPU1
> [    0.957247]        ----                    ----
> [    0.957439]   lock(&handler->enable_lock);
> [    0.957607]                                local_irq_disable();
> [    0.957793]                                lock(&irq_desc_lock_class);
> [    0.958021]                                lock(&handler->enable_lock);
> [    0.958246]   <Interrupt>
> [    0.958342]     lock(&irq_desc_lock_class);
> [    0.958501]
>                 *** DEADLOCK ***
>
> To address above, let's use raw_spin_lock_irqsave/unlock_irqrestore()
> instead of raw_spin_lock/unlock().

s/let's//



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