Re: [PATCH] rtc: max77686: fix irqf_oneshot.cocci warnings

From: Valentin Rothberg
Date: Thu Feb 18 2016 - 04:23:46 EST


Hi Alexandre,

On 2/18/16 9:51 AM, Alexandre Belloni wrote:
> On 18/02/2016 at 17:13:18 +0900, Krzysztof Kozlowski wrote :
>> On 18.02.2016 17:06, Valentin Rothberg wrote:
>>> From: kbuild test robot <fengguang.wu@xxxxxxxxx>
>>>
>>> Since commit 1c6c69525b40 ("genirq: Reject bogus threaded irq requests")
>>> threaded IRQs without a primary handler need to be requested with
>>> IRQF_ONESHOT, otherwise the request will fail.
>>>
>>> So pass the IRQF_ONESHOT flag in this case.
>>>
>>> Generated by: scripts/coccinelle/misc/irqf_oneshot.cocci
>>>
>>> CC: Laxman Dewangan <ldewangan@xxxxxxxxxx>
>>> Signed-off-by: Fengguang Wu <fengguang.wu@xxxxxxxxx>
>>> Signed-off-by: Valentin Rothberg <valentin.rothberg@xxxxxxxxxx>
>>> ---
>>> drivers/rtc/rtc-max77686.c | 4 ++--
>>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>
>> Nack, because:
>> 1. AFAIR this is a false positive.
>> 2. Was it tested? Was it reproduced? Was the bug actually spotted or
>> just coccicheck pointed this and you assumed that "request will fail"?
>>
>> Coccicheck is a great tool... but not necessarily for pointing run-time
>> bugs.
>>
>
> Definitively a false positive.
>
> Julia, I've been receiving quite a lot of those, is it possible to add a
> note that this generates false positives to try to stop people from
> blindly sending patches? I would have expected Valentin to know that
> though.

I don't have the device-specific knowledge for this issue. It really
looked like a true positive to me, so I am sorry for the noise.

A warning about false positives seems promising.

Kind regards,
Valentin