The patch titled Debug shared irqs has been removed from the -mm tree. Its filename was debug-shared-irqs.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ Subject: Debug shared irqs From: David Woodhouse <dwmw2@xxxxxxxxxxxxx> Drivers registering IRQ handlers with SA_SHIRQ really ought to be able to handle an interrupt happening before request_irq() returns. They also ought to be able to handle an interrupt happening during the start of their call to free_irq(). Let's test that hypothesis.... [bunk@xxxxxxxxx: Kconfig fixes] Signed-off-by: David Woodhouse <dwmw2@xxxxxxxxxxxxx> Cc: Arjan van de Ven <arjan@xxxxxxxxxxxxx> Signed-off-by: Jesper Juhl <jesper.juhl@xxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxx> Signed-off-by: Adrian Bunk <bunk@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/irq/manage.c | 33 +++++++++++++++++++++++++++++++++ lib/Kconfig.debug | 9 +++++++++ 2 files changed, 42 insertions(+) diff -puN kernel/irq/manage.c~debug-shared-irqs kernel/irq/manage.c --- a/kernel/irq/manage.c~debug-shared-irqs +++ a/kernel/irq/manage.c @@ -357,6 +357,7 @@ void free_irq(unsigned int irq, void *de struct irq_desc *desc; struct irqaction **p; unsigned long flags; + irqreturn_t (*handler)(int, void *) = NULL; WARN_ON(in_interrupt()); if (irq >= NR_IRQS) @@ -396,6 +397,8 @@ void free_irq(unsigned int irq, void *de /* Make sure it's not being used on another CPU */ synchronize_irq(irq); + if (action->flags & IRQF_SHARED) + handler = action->handler; kfree(action); return; } @@ -403,6 +406,17 @@ void free_irq(unsigned int irq, void *de spin_unlock_irqrestore(&desc->lock, flags); return; } +#ifdef CONFIG_DEBUG_SHIRQ + if (handler) { + /* + * It's a shared IRQ -- the driver ought to be prepared for it + * to happen even now it's being freed, so let's make sure.... + * We do this after actually deregistering it, to make sure that + * a 'real' IRQ doesn't run in parallel with our fake + */ + handler(irq, dev_id); + } +#endif } EXPORT_SYMBOL(free_irq); @@ -475,6 +489,25 @@ int request_irq(unsigned int irq, irq_ha select_smp_affinity(irq); +#ifdef CONFIG_DEBUG_SHIRQ + if (irqflags & IRQF_SHARED) { + /* + * It's a shared IRQ -- the driver ought to be prepared for it + * to happen immediately, so let's make sure.... + * We do this before actually registering it, to make sure that + * a 'real' IRQ doesn't run in parallel with our fake + */ + if (irqflags & IRQF_DISABLED) { + unsigned long flags; + + local_irq_save(flags); + handler(irq, dev_id); + local_irq_restore(flags); + } else + handler(irq, dev_id); + } +#endif + retval = setup_irq(irq, action); if (retval) kfree(action); diff -puN lib/Kconfig.debug~debug-shared-irqs lib/Kconfig.debug --- a/lib/Kconfig.debug~debug-shared-irqs +++ a/lib/Kconfig.debug @@ -77,6 +77,15 @@ config DEBUG_KERNEL Say Y here if you are developing drivers or trying to debug and identify kernel problems. +config DEBUG_SHIRQ + bool "Debug shared IRQ handlers" + depends on DEBUG_KERNEL && GENERIC_HARDIRQS + help + Enable this to generate a spurious interrupt as soon as a shared + interrupt handler is registered, and just before one is deregistered. + Drivers ought to be able to handle interrupts coming in at those + points; some don't and need to be caught. + config LOG_BUF_SHIFT int "Kernel log buffer size (16 => 64KB, 17 => 128KB)" if DEBUG_KERNEL range 12 21 _ Patches currently in -mm which might be from dwmw2@xxxxxxxxxxxxx are origin.patch new-toplevel-target-headers_check_all.patch git-mtd.patch - To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html