diff options
| author | Jiri Kosina <jkosina@suse.cz> | 2013-03-21 00:21:21 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-03-25 13:22:32 -0700 |
| commit | 54f69b92f037f4ff5779e5645ab714dee5b59095 (patch) | |
| tree | cd935d3d36afbe0627a64c0774b662696c9c06d7 | |
| parent | 4c6e22b8a93ef038b70661e590de250a09417af7 (diff) | |
dummy-irq: introduce a dummy IRQ handler driver
This module accepts a single 'irq' parameter, which it should register for.
Its sole purpose is to help with debugging of IRQ sharing problems, by
force-enabling IRQ that would otherwise be disabled.
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/misc/Kconfig | 8 | ||||
| -rw-r--r-- | drivers/misc/Makefile | 1 | ||||
| -rw-r--r-- | drivers/misc/dummy-irq.c | 59 |
3 files changed, 68 insertions, 0 deletions
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig index e83fdfe0c8ca..69bb79d6dd54 100644 --- a/drivers/misc/Kconfig +++ b/drivers/misc/Kconfig @@ -93,6 +93,14 @@ config ATMEL_TCB_CLKSRC_BLOCK TC can be used for other purposes, such as PWM generation and interval timing. +config DUMMY_IRQ + tristate "Dummy IRQ handler" + default n + ---help--- + This module accepts a single 'irq' parameter, which it should register for. + The sole purpose of this module is to help with debugging of systems on + which spurious IRQs would happen on disabled IRQ vector. + config IBM_ASM tristate "Device driver for IBM RSA service processor" depends on X86 && PCI && INPUT diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile index 3e2faa0939b2..865cbc6a7ae1 100644 --- a/drivers/misc/Makefile +++ b/drivers/misc/Makefile @@ -13,6 +13,7 @@ obj-$(CONFIG_ATMEL_TCLIB) += atmel_tclib.o obj-$(CONFIG_BMP085) += bmp085.o obj-$(CONFIG_BMP085_I2C) += bmp085-i2c.o obj-$(CONFIG_BMP085_SPI) += bmp085-spi.o +obj-$(CONFIG_DUMMY_IRQ) += dummy-irq.o obj-$(CONFIG_ICS932S401) += ics932s401.o obj-$(CONFIG_LKDTM) += lkdtm.o obj-$(CONFIG_TIFM_CORE) += tifm_core.o diff --git a/drivers/misc/dummy-irq.c b/drivers/misc/dummy-irq.c new file mode 100644 index 000000000000..7014167e2c61 --- /dev/null +++ b/drivers/misc/dummy-irq.c @@ -0,0 +1,59 @@ +/* + * Dummy IRQ handler driver. + * + * This module only registers itself as a handler that is specified to it + * by the 'irq' parameter. + * + * The sole purpose of this module is to help with debugging of systems on + * which spurious IRQs would happen on disabled IRQ vector. + * + * Copyright (C) 2013 Jiri Kosina + */ + +/* + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + */ +#include <linux/module.h> +#include <linux/irq.h> +#include <linux/interrupt.h> + +static int irq; + +static irqreturn_t dummy_interrupt(int irq, void *dev_id) +{ + static int count = 0; + + if (count == 0) { + printk(KERN_INFO "dummy-irq: interrupt occured on IRQ %d\n", + irq); + count++; + } + + return IRQ_NONE; +} + +static int __init dummy_irq_init(void) +{ + if (request_irq(irq, &dummy_interrupt, IRQF_SHARED, "dummy_irq", &irq)) { + printk(KERN_ERR "dummy-irq: cannot register IRQ %d\n", irq); + return -EIO; + } + printk(KERN_INFO "dummy-irq: registered for IRQ %d\n", irq); + return 0; +} + +static void __exit dummy_irq_exit(void) +{ + printk(KERN_INFO "dummy-irq unloaded\n"); + free_irq(irq, &irq); +} + +module_init(dummy_irq_init); +module_exit(dummy_irq_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Jiri Kosina"); +module_param(irq, uint, 0444); +MODULE_PARM_DESC(irq, "The IRQ to register for"); |