From ce753ad1549cbe9ccaea4c06a1f5fa47432c8289 Mon Sep 17 00:00:00 2001
From: Sergey Shtylyov <s.shtylyov@omp.ru>
Date: Fri, 11 Mar 2022 22:35:29 +0300
Subject: [PATCH] platform: finally disallow IRQ0 in platform_get_irq() and its
ilk
The commit a85a6c86c25b ("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: a85a6c86c25b ("driver core: platform: Clarify that IRQ 0 is invalid")
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Link: https://lore.kernel.org/r/025679e1-1f0a-ae4b-4369-01164f691511@omp.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/base/platform.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index b684157b7f2f9..5259f1f931873 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -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;
}
--
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