Thread (14 messages) 14 messages, 3 authors, 2020-09-16

Re: [PATCH v2 1/4] Input: ep93xx_keypad - Fix handling of platform_get_irq() error

From: Krzysztof Kozlowski <krzk@kernel.org>
Date: 2020-09-15 22:34:02
Also in: linux-input, lkml

On Mon, 14 Sep 2020 at 08:51, Dmitry Torokhov [off-list ref] wrote:
Hi Krzysztof,

On Fri, Aug 28, 2020 at 04:57:41PM +0200, Krzysztof Kozlowski wrote:
quoted
platform_get_irq() returns -ERRNO on error.  In such case comparison
to 0 would pass the check.
platform_get_irq() is a bit of a mess. Historically we allowed defining
interrupt resource with r->start == 0 and for such cases non-OF non-ACPI
code will return 0 from platform_get_irq() to indicate that IRQ is not
assigned.

We either need to stop doing this in platform_get_irq(), or the
conditions in this patch and followups should be "irq <= 0" and we need
to make sure we do not accidentally return 0 from probe ...
Hi,

It's then contradictory to platform_get_irq documentation which
explicitly says - zero will not be returned on error. This was also
clarified in commit e330b9a6bb35 ("platform: don't return 0 from
platform_get_irq[_byname]() on error").

As I understood the input drivers code, they check for errors so the
coe in my patch is correct. Any "<=0" is not correct with current
documentation and implementation.

Best regards,
Krzysztof

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help