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Commit 1cef8e41 authored by Russell King's avatar Russell King Committed by Samuel Ortiz
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mfd: twl4030 irq fixes 

The TWL4030 IRQ handler has a bug which leads to spinlock lock-up. It is
calling the 'unmask' function in a process context. :The mask/unmask/ack
functions are only designed to be called from the IRQ handler code,
or the proper API interfaces found in linux/interrupt.h.

Also there is no need to have IRQ chaining mechanism. The right way to
handle this is to claim the parent interrupt as a standard interrupt
and arrange for handle_twl4030_pih to take care of the rest of the devices.

Mail thread on this issue can be found at:
http://marc.info/?l=linux-arm-kernel&m=124629940123396&w=2



Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
Tested-by: default avatarSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: default avatarTony Lindgren <tony@atomide.com>
Signed-off-by: default avatarSamuel Ortiz <sameo@linux.intel.com>
parent a33a052f

drivers/mfd/twl4030-irq.c

+24 −31
Original line number Diff line number Diff line
@@ -180,14 +180,9 @@ static struct completion irq_event; 
static int twl4030_irq_thread(void *data)

{

	long irq = (long)data;

	struct irq_desc *desc = irq_to_desc(irq);

	static unsigned i2c_errors;

	static const unsigned max_i2c_errors = 100;



	if (!desc) {

		pr_err("twl4030: Invalid IRQ: %ld\n", irq);

		return -EINVAL;

	}



	current->flags |= PF_NOFREEZE;
@@ -240,7 +235,7 @@ static int twl4030_irq_thread(void *data) 
		}

		local_irq_enable();



		desc->chip->unmask(irq);

		enable_irq(irq);

	}



	return 0;
@@ -255,25 +250,13 @@ static int twl4030_irq_thread(void *data) 
 * thread.  All we do here is acknowledge and mask the interrupt and wakeup

 * the kernel thread.

 */

static void handle_twl4030_pih(unsigned int irq, struct irq_desc *desc)

static irqreturn_t handle_twl4030_pih(int irq, void *devid)

{

	/* Acknowledge, clear *AND* mask the interrupt... */

	desc->chip->ack(irq);

	complete(&irq_event);

}



static struct task_struct *start_twl4030_irq_thread(long irq)

{

	struct task_struct *thread;



	init_completion(&irq_event);

	thread = kthread_run(twl4030_irq_thread, (void *)irq, "twl4030-irq");

	if (!thread)

		pr_err("twl4030: could not create irq %ld thread!\n", irq);



	return thread;

	disable_irq_nosync(irq);

	complete(devid);

	return IRQ_HANDLED;

}



/*----------------------------------------------------------------------*/



/*
@@ -734,18 +717,28 @@ int twl_init_irq(int irq_num, unsigned irq_base, unsigned irq_end) 
	}



	/* install an irq handler to demultiplex the TWL4030 interrupt */

	task = start_twl4030_irq_thread(irq_num);

	if (!task) {

		pr_err("twl4030: irq thread FAIL\n");

		status = -ESRCH;

		goto fail;

	}



	set_irq_data(irq_num, task);

	set_irq_chained_handler(irq_num, handle_twl4030_pih);



	return status;

	init_completion(&irq_event);



	status = request_irq(irq_num, handle_twl4030_pih, IRQF_DISABLED,

				"TWL4030-PIH", &irq_event);

	if (status < 0) {

		pr_err("twl4030: could not claim irq%d: %d\n", irq_num, status);

		goto fail_rqirq;

	}



	task = kthread_run(twl4030_irq_thread, (void *)irq_num, "twl4030-irq");

	if (IS_ERR(task)) {

		pr_err("twl4030: could not create irq %d thread!\n", irq_num);

		status = PTR_ERR(task);

		goto fail_kthread;

	}

	return status;

fail_kthread:

	free_irq(irq_num, &irq_event);

fail_rqirq:

	/* clean up twl4030_sih_setup */

fail:

	for (i = irq_base; i < irq_end; i++)

		set_irq_chip_and_handler(i, NULL, NULL);