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mfd: twl4030 irq fixes

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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: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This commit is contained in:
Russell King 2009-07-27 11:30:48 +05:30 committed by Samuel Ortiz
parent a33a052f19
commit 1cef8e4107
1 changed files with 24 additions and 31 deletions
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55
drivers/mfd/twl4030-irq.c
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@ -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);
disable_irq_nosync(irq);
complete(devid);
return IRQ_HANDLED;
}
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;
}
/*----------------------------------------------------------------------*/
/*
@ -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;
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;
}
set_irq_data(irq_num, task);
set_irq_chained_handler(irq_num, handle_twl4030_pih);
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);