linux-kernel - Re: Disabling an interrupt in the handler locks the system up

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <alpine.DEB.2.20.1610212147420.4855@nanos>
Date:   Fri, 21 Oct 2016 21:49:35 +0200 (CEST)
From:   Thomas Gleixner <tglx@...utronix.de>
To:     Mason <slash.tmp@...e.fr>
cc:     Marc Zyngier <marc.zyngier@....com>,
        Jason Cooper <jason@...edaemon.net>,
        LKML <linux-kernel@...r.kernel.org>,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>,
        Sebastian Frias <sf84@...oste.net>
Subject: Re: Disabling an interrupt in the handler locks the system up

On Fri, 21 Oct 2016, Mason wrote:
> On 21/10/2016 21:14, Marc Zyngier wrote:
> > If connecting a device that signals its interrupt as level low to an
> > input line configured as level high doesn't strike you as a major
> > issue, nothing will. At that point, you can put anything you want in
> > your DT.
> 
> If I understand correctly, you are saying that I should have
> specified IRQ_TYPE_LEVEL_LOW, instead of IRQ_TYPE_LEVEL_HIGH?
> 
> If the HW outputs 1 when idle, and 0 when busy, that
> is level low? (Sorry if this is obvious, I'm absolutely
> clueless in this subject matter.)

We describe the level which is raising the interrupt. So in your case the
line goes to 0 when the interrupt is active, so the level is LOW.

Thanks,

	tglx