I am having a kernel thread that waits on a completion object.

I am also having an ISR that wakes up the thread when ever an interrupt occurs.
The thread calls wait_completion_interruptible and waits for "completion" event.

What is happening is Even though i get the interrupt - The ISR calls 'complete'

The Thread does not wakeup.

I dont know why?.

I notice that i replaced wait_completion_interruptible with
wait_completion_timeout.

What happens is i keep getting the messages. As soon as the ISR
triggers the completion event. The threads stops/gets killed.

I dont know whats happening.


Could anyone help me on this.

Appending my code

Regards,
veda



#include
#include
#include
#include
#include
#include
#include
#include

MODULE_AUTHOR("Newbee");
MODULE_DESCRIPTION("Wait Interruptible Demo Driver");

static int r_init(void);
static void r_cleanup(void);

module_init(r_init);
module_exit(r_cleanup);


static int information = 0x100;
static int id = 99;
static struct completion touch_completion;
static struct completion thread_comp;
struct task_struct *kthread;

int printmsgd(void *param);

static irqreturn_t attn_isr( int irq, void *info)
{
printk ("Got an Interrupt\n");

complete(&touch_completion);
}

static int r_init(void)
{
int retval;
init_completion(&touch_completion);
init_completion(&thread_comp);
if(omap_request_gpio( 140 ) < 0)
{
printk("Error: failed to request gpio\n");
}

printk ("interrupt mode...\n");
omap_set_gpio_direction( 140, 1);

if(( retval = request_irq(OMAP_GPIO_IRQ(140), attn_isr,
IRQF_TRIGGER_LOW, "test-irq", &information )))
{
printk ("Error: Unable to do request irq\n");
return -1;
}

kthread = kthread_run(&printmsgd, &id, "printmsgd");

printk ("kthread run:%x\n", kthread);


return 0;
}

static void r_cleanup(void)
{
complete(&touch_completion); /* Kick the thread awake */
if (kthread) wait_for_completion(&thread_comp);
return ;
}

int printmsgd(void *param)
{
int ret;

// daemonize("printmsgd");

while (!kthread_should_stop()) {
ret = wait_for_completion_interruptible(&touch_completion);
printk ("printmsgd says hi:%d\n", ret);
}
complete_and_exit(&thread_comp, 0);
}
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