Hello, On Mon Feb 19, 2024 at 4:48 PM CET, Bartosz Golaszewski wrote: > On Wed, Feb 14, 2024 at 5:24 PM Théo Lebrun <theo.lebrun@xxxxxxxxxxx> wrote: > > > > Support a single IRQs used by multiple GPIO banks. Change the IRQ > > handler type from a chained handler (as used by gpiolib > > for ->parent_handler) to a threaded IRQ. > > > > Use a fake raw spinlock to ensure generic_handle_irq() is called in a > > no-irq context. See Documentation/driver-api/gpio/driver.rst, "CHAINED > > CASCADED GPIO IRQCHIPS" for additional information. > > > > Any reason for not using preempt_disable()? I did what the doc recommended: > The generic_handle_irq() is expected to be called with IRQ disabled, > so the IRQ core will complain if it is called from an IRQ handler which is > forced to a thread. The "fake?" raw lock can be used to work around this > problem:: > > raw_spinlock_t wa_lock; > static irqreturn_t omap_gpio_irq_handler(int irq, void *gpiobank) > unsigned long wa_lock_flags; > raw_spin_lock_irqsave(&bank->wa_lock, wa_lock_flags); > generic_handle_irq(irq_find_mapping(bank->chip.irq.domain, bit)); > raw_spin_unlock_irqrestore(&bank->wa_lock, wa_lock_flags); If you confirm I should be using preempt_disable() that's what I'll do in the next revision. I could even throw in a documentation patch if the advice is outdated. Thanks Bartosz, -- Théo Lebrun, Bootlin Embedded Linux and Kernel engineering https://bootlin.com
