"Trying to free already-free IRQ 9", but it wasn't freed by me
Hi, atm I'm writing a kernel module for an embedded ARM device. This module uses IRQ9. If i remove the module, the kernel tells me that: ------------[ cut here ]------------ WARNING: at kernel/irq/manage.c:858 __free_irq+0x84/0x154() Trying to free already-free IRQ 9 Modules linked in: adc_demo_irq(P-) g_ether pegasus mii [<c0028794>] (unwind_backtrace+0x0/0xd0) from [<c003b504>] (warn_slowpath_common+0x48/0x60) [<c003b504>] (warn_slowpath_common+0x48/0x60) from [<c003b554>] (warn_slowpath_fmt+0x24/0x30) [<c003b554>] (warn_slowpath_fmt+0x24/0x30) from [<c005fa00>] (__free_irq+0x84/0x154) [<c005fa00>] (__free_irq+0x84/0x154) from [<c005fb0c>] (free_irq+0x3c/0x5c) [<c005fb0c>] (free_irq+0x3c/0x5c) from [<bf01e18c>] (cleanup_module+0x4c/0x60 [adc_demo_irq]) [<bf01e18c>] (cleanup_module+0x4c/0x60 [adc_demo_irq]) from [<c005b898>] (sys_delete_module+0x1c4/0x238) [<c005b898>] (sys_delete_module+0x1c4/0x238) from [<c0022dc0>] (ret_fast_syscall+0x0/0x28) ---[ end trace 60d7a16d878ac0b3 ]--- adc testing module removed ------------[ cut here ]------------ The message "adc testing module removed" comes from my module *after* free_irq() via printk, so the module exit routine works till the end. This is my code (only the IRQ related part): irqreturn_t adc_irq_handler(int irq, void *dev_id) { ... do someting ... return IRQ_HANDLED; } int init_module(void) { int32_t retval; ... retval = request_irq(ADC_IRQ, adc_irq_handler, IRQF_SHARED, "lpc313x adc irq", (void *)(adc_irq_handler)); ... return retval; } void cleanup_module(void) { ... free_irq(ADC_IRQ, NULL); /* remove interrupt handler */ ... return; } I hope anyone of you can help me with that problem. If you need more information, i'll send it Greetings, Nils
Hi Nils,
void cleanup_module(void) { ... free_irq(ADC_IRQ, NULL); /* remove interrupt handler */ ... return; }
You should not pass NULL here. It should be the unique cookie that you passed in request_irq (adc_irq_handler in your case) since you have used IRQF_SHARED which means you want to share your interrupt line. Also check whether you really want to share your interrupt line and also if you want to use "(void *)(adc_irq_handler)" as the unique identification. HTH! Regards Mayur On Tue, Feb 7, 2012 at 7:45 PM, nils.stec <nils.stec@googlemail.com> wrote:
Hi,
atm I'm writing a kernel module for an embedded ARM device. This module uses IRQ9.
If i remove the module, the kernel tells me that:
------------[ cut here ]------------ WARNING: at kernel/irq/manage.c:858 __free_irq+0x84/0x154() Trying to free already-free IRQ 9 Modules linked in: adc_demo_irq(P-) g_ether pegasus mii [<c0028794>] (unwind_backtrace+0x0/0xd0) from [<c003b504>] (warn_slowpath_common+0x48/0x60) [<c003b504>] (warn_slowpath_common+0x48/0x60) from [<c003b554>] (warn_slowpath_fmt+0x24/0x30) [<c003b554>] (warn_slowpath_fmt+0x24/0x30) from [<c005fa00>] (__free_irq+0x84/0x154) [<c005fa00>] (__free_irq+0x84/0x154) from [<c005fb0c>] (free_irq+0x3c/0x5c) [<c005fb0c>] (free_irq+0x3c/0x5c) from [<bf01e18c>] (cleanup_module+0x4c/0x60 [adc_demo_irq]) [<bf01e18c>] (cleanup_module+0x4c/0x60 [adc_demo_irq]) from [<c005b898>] (sys_delete_module+0x1c4/0x238) [<c005b898>] (sys_delete_module+0x1c4/0x238) from [<c0022dc0>] (ret_fast_syscall+0x0/0x28) ---[ end trace 60d7a16d878ac0b3 ]--- adc testing module removed ------------[ cut here ]------------
The message "adc testing module removed" comes from my module **after**free_irq() via printk, so the module exit routine works till the end.
This is my code (only the IRQ related part):
irqreturn_t adc_irq_handler(int irq, void *dev_id) {
... do someting ...
return IRQ_HANDLED; }
int init_module(void) { int32_t retval; ... retval = request_irq(ADC_IRQ, adc_irq_handler, IRQF_SHARED, "lpc313x adc irq", (void *)(adc_irq_handler)); ... return retval; }
void cleanup_module(void) { ... free_irq(ADC_IRQ, NULL); /* remove interrupt handler */ ... return; }
I hope anyone of you can help me with that problem. If you need more information, i'll send it
Greetings, Nils
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