Commit ce753ad1 authored by Sergey Shtylyov's avatar Sergey Shtylyov Committed by Greg Kroah-Hartman
Browse files

platform: finally disallow IRQ0 in platform_get_irq() and its ilk 



The commit a85a6c86 ("driver core: platform: Clarify that IRQ 0 is
invalid") only calls WARN() when IRQ0 is about to be returned, however
using IRQ0 is considered invalid (according to Linus) outside the arch/
code where it's used by the i8253 drivers. Many driver subsystems treat
0 specially (e.g. as an indication of the polling mode by libata), so
the users of platform_get_irq[_byname]() in them would have to filter
out IRQ0 explicitly and this (quite obviously) doesn't scale...
Let's finally get this straight and return -EINVAL instead of IRQ0!

Fixes: a85a6c86 ("driver core: platform: Clarify that IRQ 0 is invalid")
Acked-by: default avatarMarc Zyngier <maz@kernel.org>
Signed-off-by: default avatarSergey Shtylyov <s.shtylyov@omp.ru>
Link: https://lore.kernel.org/r/025679e1-1f0a-ae4b-4369-01164f691511@omp.ru


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a72b6dff

drivers/base/platform.c

+4 −2
Original line number Diff line number Diff line
@@ -231,7 +231,8 @@ int platform_get_irq_optional(struct platform_device *dev, unsigned int num) 
out_not_found:

	ret = -ENXIO;

out:

	WARN(ret == 0, "0 is an invalid IRQ number\n");

	if (WARN(!ret, "0 is an invalid IRQ number\n"))

		return -EINVAL;

	return ret;

}

EXPORT_SYMBOL_GPL(platform_get_irq_optional);
@@ -446,7 +447,8 @@ static int __platform_get_irq_byname(struct platform_device *dev, 


	r = platform_get_resource_byname(dev, IORESOURCE_IRQ, name);

	if (r) {

		WARN(r->start == 0, "0 is an invalid IRQ number\n");

		if (WARN(!r->start, "0 is an invalid IRQ number\n"))

			return -EINVAL;

		return r->start;

	}