From 1cef8e41073efe47e809f49670eb461307e52ccc Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 27 Jul 2009 11:30:48 +0530 Subject: [PATCH] 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: Russell King Tested-by: Santosh Shilimkar Acked-by: Tony Lindgren Signed-off-by: Samuel Ortiz --- drivers/mfd/twl4030-irq.c | 55 +++++++++++++++++---------------------- 1 file changed, 24 insertions(+), 31 deletions(-) diff --git a/drivers/mfd/twl4030-irq.c b/drivers/mfd/twl4030-irq.c index bae61b22501c..7d430835655f 100644 --- a/drivers/mfd/twl4030-irq.c +++ b/drivers/mfd/twl4030-irq.c @@ -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);