From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Nizette Subject: [PATCH 0/9] Fix unsafe disable_irq usage Date: Thu, 16 Apr 2009 15:54:05 +1000 Message-ID: <1239861245.29831.113.camel@linux-51e8.site> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel Cc: dan.j.williams@intel.com, Eric Miao , linux@arm.linux.org.uk, dmitry.torokhov@gmail.com, p_gortmaker@yahoo.com, David Brownell , sameo@linux.intel.com, linux-omap@vger.kernel.org, pierre@ossman.eu, linux-input@vger.kernel.org List-Id: linux-input@vger.kernel.org After being bitten by unsafe usage of disable_irq from within that irq's handler [1], I went through and used Coccinelle to audit the rest of drivers/ too. This turned up 9 more unsafe usages. As Haavard pointed out in that thread, disable_irq waits for running handlers of an irq to complete before returning. When a handler disable_irq's its own irq then we see a deadlock. Note that this wasn't actually observed in the wild until the recent merge of commit 3aa551c9b4c40018f0e261a178e3d25478dc04a9 Author: Thomas Gleixner Date: Mon Mar 23 18:28:15 2009 +0100 genirq: add threaded interrupt handler support Add support for threaded interrupt handlers Regards, --Ben. [1] http://lkml.org/lkml/2009/4/15/498