From: Gerlando Falauto <gerlando.falauto@keymile.com>
To: linux-kernel@vger.kernel.org
Cc: Gerlando Falauto <gerlando.falauto@keymile.com>,
Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
Holger Brunck <holger.brunck@keymile.com>
Subject: [PATCH 0/1] genirq: drop synchronize_irq() unless CONFIG_SMP
Date: Wed, 18 Jan 2012 08:59:56 +0100 [thread overview]
Message-ID: <1326873597-19188-1-git-send-email-gerlando.falauto@keymile.com> (raw)
Up until 2.6.28, synchronize_irq() was only implemented
when CONFIG_SMP was defined, and this was consistent
between kernel/irq/manage.c and include/linux/hardirq.h
At some point before 2.6.29, a second condition
became necessary, CONFIG_GENERIC_HARDIRQS, and this was
still consistent in that both files showed some
#if defined(CONFIG_SMP) && defined(CONFIG_GENERIC_HARDIRQS)
Then before 2.6.30:
:commit 3aa551c9b4c40018f0e261a178e3d25478dc04a9
:Author: Thomas Gleixner <tglx@linutronix.de>
:Date: Mon Mar 23 18:28:15 2009 +0100
:
: genirq: add threaded interrupt handler support
changed this so that include/linux/hardirq.h declares a function when
#if defined(CONFIG_SMP) || defined(CONFIG_GENERIC_HARDIRQS)
whereas kernel/irq/manage.c always defines one anyway.
Since synchronize_irq() only makes sense under SMP, we both declare
and define one when CONFIG_SMP=y.
CONFIG_GENERIC_HARDIRQS is a necessary condition for compiling
kernel/irq/manage.c, so if you are not using it you should implement
your own.
This fixes startup deadlocks in SMP-unaware drivers which call
disable_irq() within its own handler, and used to work
(by chance), up until 2.6.29.
Other drivers were fixed by changing disable_irq() to
disable_irq_nosync(), with references to the above patch,
like for instance:
:commit f43ab901005c2bb3c5440e91b6efae9f5db02e7c
:Author: Nelson Castillo <arhuaco@freaks-unidos.net>
:Date: Tue May 12 13:26:47 2009 -0700
:
: mfd: pcf50633: fix unsafe disable_irq()
:commit 950312ce22696ddfa42a957bdadaa9c24151e679
:Author: Andrew Randrianasulu <randrik_a@yahoo.com>
:Date: Thu May 14 11:29:27 2009 -0700
:
: MIPS: IP32: Fix hang on shutdown in power button interrupt handler.
:commit 7e9e05cad94217498e4d9bd6ef7137b4e9e7ed64
:Author: Ralf Baechle <ralf@linux-mips.org>
:Date: Sat May 16 12:23:45 2009 +0100
:
: MIPS: IP22: Fix hang in power button interrupt handler
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Holger Brunck <holger.brunck@keymile.com>
Signed-off-by: Gerlando Falauto <gerlando.falauto@keymile.com>
Gerlando Falauto (1):
genirq: drop synchronize_irq() unless CONFIG_SMP
include/linux/hardirq.h | 2 +-
kernel/irq/manage.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
next reply other threads:[~2012-01-18 8:00 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-18 7:59 Gerlando Falauto [this message]
2012-01-18 7:59 ` [PATCH 1/1] genirq: drop synchronize_irq() unless CONFIG_SMP Gerlando Falauto
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