From 69dd3d8e29e294caaf63eb5e8a72d250279f9e5f Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 23 Aug 2011 10:36:51 -0700 Subject: [PATCH] Revert "irq: Always set IRQF_ONESHOT if no primary handler is specified" This reverts commit f3637a5f2e2eb391ff5757bc83fb5de8f9726464. It turns out that this breaks several drivers, one example being OMAP boards which use the on-board OMAP UARTs and the omap-serial driver that will not boot to userspace after the commit. Paul Walmsley reports that enabling CONFIG_DEBUG_SHIRQ reveals 'IRQ handler type mismatch' errors: IRQ handler type mismatch for IRQ 74 current handler: serial idle ... and the reason is that setting IRQF_ONESHOT will now result in those interrupt handlers having different IRQF flags, and thus being unsharable. So the commit log in the reverted commit: "Since it is required for those users and there is no difference for others it makes sense to add this flag unconditionally." is simply not true: there may not be any difference from a "actions at irq time", but there is a *big* difference wrt this flag testing irq management (see __setup_irq() in kernel/irq/manage.c). One solution may be to stop verifying IRQF_ONESHOT in __setup_irq(), but right now the safe course of action is to revert the change. Let's revisit this in a later merge window. Reported-by: Paul Walmsley Cc: Sebastian Andrzej Siewior Requested-by: Alan Cox Acked-by: Thomas Gleixner Signed-off-by: Linus Torvalds --- kernel/irq/manage.c | 1 - 1 file changed, 1 deletion(-) diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 2e94258..9b956fa 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -1331,7 +1331,6 @@ int request_threaded_irq(unsigned int irq, irq_handler_t handler, if (!thread_fn) return -EINVAL; handler = irq_default_primary_handler; - irqflags |= IRQF_ONESHOT; } action = kzalloc(sizeof(struct irqaction), GFP_KERNEL); -- 2.7.4