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From: Arnd Bergmann <arnd@arndb.de>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Meelis Roos <mroos@linux.ee>, Ingo Molnar <mingo@kernel.org>,
	linux-tip-commits@vger.kernel.org,
	kbuild test robot <fengguang.wu@intel.com>
Subject: Re: [tip:irq/urgent] genirq: Make legacy autoprobing work again
Date: Thu, 1 Feb 2018 12:35:33 +0100	[thread overview]
Message-ID: <CAK8P3a0udHSrqBZ3BtJAqa4oUJ2wGuWZGZ6e=62OxLXbL_9X3A@mail.gmail.com> (raw)
In-Reply-To: <CAMuHMdUfGUXmjFdyjLdBiyOayy22p-91Oonp-hK4x0hqcOnPUA@mail.gmail.com>

On Thu, Feb 1, 2018 at 9:15 AM, Geert Uytterhoeven <geert@linux-m68k.org> wrote:

>> +++ b/kernel/irq/chip.c
>> @@ -294,11 +294,11 @@ int irq_activate(struct irq_desc *desc)
>>         return 0;
>>  }
>>
>> -void irq_activate_and_startup(struct irq_desc *desc, bool resend)
>> +int irq_activate_and_startup(struct irq_desc *desc, bool resend)
>>  {
>>         if (WARN_ON(irq_activate(desc)))
>>                 return;
>
> As reported by 0day, this should return something.
>
> if CONFIG_IRQ_DOMAIN=n or CONFIG_IRQ_DOMAIN_HIERARCHY=n,
> irq_activate() will never return 1, and the code path can be eliminated.
>
> BTW, is gcc becoming too smart, and already eliminating code before it
> generates warnings for it? Recently I've seen some other cases where buggy
> code was not warned about, as it was considered not having any impact.
>

I've tried my collection of compiler versions, and they produce a warning here
on my box.

       Arnd

  parent reply	other threads:[~2018-02-01 11:35 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-29 16:20 4.15: WARNING: CPU: 3 PID: 258 at kernel/irq/chip.c:244 __irq_startup+0x80/0x100 Meelis Roos
2018-01-29 16:35 ` Thomas Gleixner
2018-01-30 18:36   ` Thomas Gleixner
2018-01-31  7:21     ` Meelis Roos
2018-01-31  7:58       ` Thomas Gleixner
2018-01-31  8:09         ` Ingo Molnar
2018-01-31 11:23           ` Meelis Roos
2018-01-31 11:59             ` Ingo Molnar
2018-01-31  9:54     ` [tip:irq/urgent] genirq: Make legacy autoprobing work again tip-bot for Thomas Gleixner
2018-02-01  8:15       ` Geert Uytterhoeven
2018-02-01  9:56         ` Thomas Gleixner
2018-02-01 11:35         ` Arnd Bergmann [this message]
2018-02-01  9:58     ` tip-bot for Thomas Gleixner
2018-02-01 10:12     ` tip-bot for Thomas Gleixner

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