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| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2022-11-10 18:54:35 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-11-11 10:28:38 +0100 |
| commit | 8836402d4b208b2211fc60538ff45d6bb3b73a64 (patch) | |
| tree | 14cc0e7f222ac67a89c32ab2244db6966d2ce123 /drivers/usb/host/ehci-grlib.c | |
| parent | 46ed6026ca2181c917c8334a82e3eaf40a6234dd (diff) | |
| download | lwn-8836402d4b208b2211fc60538ff45d6bb3b73a64.tar.gz lwn-8836402d4b208b2211fc60538ff45d6bb3b73a64.zip | |
usb: Check !irq instead of irq == NO_IRQ
NO_IRQ is a relic from the old days. It is not used anymore in core
functions. By the way, function irq_of_parse_and_map() returns value 0
on error.
In some drivers, NO_IRQ is erroneously used to check the return of
irq_of_parse_and_map().
It is not a real bug today because the only architectures using the
drivers being fixed by this patch define NO_IRQ as 0, but there are
architectures which define NO_IRQ as -1. If one day those
architectures start using the non fixed drivers, there will be a
problem.
Long time ago Linus advocated for not using NO_IRQ, see
https://lkml.org/lkml/2005/11/21/221 . He re-iterated the same view
recently in https://lkml.org/lkml/2022/10/12/622
So test !irq instead of tesing irq == NO_IRQ.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/13feefdf6b240817944e6441e26a8ddc1d81ced1.1668102802.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/host/ehci-grlib.c')
| -rw-r--r-- | drivers/usb/host/ehci-grlib.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/usb/host/ehci-grlib.c b/drivers/usb/host/ehci-grlib.c index a2c3b4ec8a8b..0717f2ccf49d 100644 --- a/drivers/usb/host/ehci-grlib.c +++ b/drivers/usb/host/ehci-grlib.c @@ -99,7 +99,7 @@ static int ehci_hcd_grlib_probe(struct platform_device *op) hcd->rsrc_len = resource_size(&res); irq = irq_of_parse_and_map(dn, 0); - if (irq == NO_IRQ) { + if (!irq) { dev_err(&op->dev, "%s: irq_of_parse_and_map failed\n", __FILE__); rv = -EBUSY; |