Messages in this thread | | | Date | Wed, 16 Dec 2020 09:36:17 +0000 | From | Marc Zyngier <> | Subject | Re: [PATCH v4 2/4] gpio: visconti: Add Toshiba Visconti GPIO support |
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On 2020-12-16 09:11, Nobuhiro Iwamatsu wrote:
[...]
>> > + for (i = 0; i < num_irq; i++) { >> > + desc = irq_to_desc(priv->irq[i]); >> > + desc->status_use_accessors |= IRQ_NOAUTOEN; >> > + if (devm_request_irq(dev, priv->irq[i], >> > + visconti_gpio_irq_handler, 0, name, priv)) { >> > + dev_err(dev, "failed to request IRQ[%d]\n", i); >> > + return -ENOENT; >> > + } >> > + } >> >> This should not be needed either when using hiearchical IRQs, >> also the irqchip maintainers will beat us up for poking around in the >> descs like this. > > I understand that the processing equivalent to request_irq() is > processed > by the irqchip frame work (or GIC driver). Is this correct?
request_irq() is reserved to endpoint drivers (the driver for the device driving the IRQ line). If this is indeed a hierarchical irqchip, the line allocation will be driven from the GPIO framework, and request_irq() will perform the activation. There isn't anything that this driver should do directly other than configuring its own state and passing the request along to the parent controller.
And yes, mucking with the irq descriptor will get you in massive trouble, never do that.
Thanks,
M. -- Jazz is not dead. It just smells funny...
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