mfd: twl4030-core irq simplification

Simplify twl4030 IRQ handling by removing a needless custom flow
handler.  The top level IRQs, from the PIH, are well suited for
handle_simple_irq() ... they can't be acked or masked.

Switching resolves some issues with how IRQs were dispatched.
Notably, abuse of desc->status, IRQ accounting, and handling
of various faults.

In short, use standard genirq code.

Drivers that request_irq() to the PIH will need to pay more
attention to things like setting IRQF_DISABLED (since it's
no longer ignored), and making I2C calls from handlers (you'll
need a lockdep workaround).

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Samuel Ortiz <sameo@openedhand.com>

diff --git a/drivers/mfd/twl4030-core.c b/drivers/mfd/twl4030-core.c
index 4af1624987c5d4578c15f6ee97c9307605caf57f..fd9a0160202cbf9c15105049ac2847ef6477b2fc 100644 (file)
--- a/drivers/mfd/twl4030-core.c
+++ b/drivers/mfd/twl4030-core.c
@@ -535,68 +535,6 @@ EXPORT_SYMBOL(twl4030_i2c_read_u8);
 
 /*----------------------------------------------------------------------*/
 
-/*
- * do_twl4030_module_irq() is the desc->handle method for each of the twl4030
- * module interrupts that doesn't chain to another irq_chip (GPIO, power, etc).
- * It executes in kernel thread context.  On entry, cpu interrupts are disabled.
- */
-static void do_twl4030_module_irq(unsigned int irq, irq_desc_t *desc)
-{
-       struct irqaction *action;
-       const unsigned int cpu = smp_processor_id();
-
-       /*
-        * Earlier this was desc->triggered = 1;
-        */
-       desc->status |= IRQ_LEVEL;
-
-       /*
-        * The desc->handle method would normally call the desc->chip->ack
-        * method here, but we won't bother since our ack method is NULL.
-        */
-
-       if (!desc->depth) {
-               kstat_cpu(cpu).irqs[irq]++;
-
-               action = desc->action;
-               if (action) {
-                       int ret;
-                       int status = 0;
-                       int retval = 0;
-
-                       local_irq_enable();
-
-                       do {
-                               /* Call the ISR with cpu interrupts enabled */
-                               ret = action->handler(irq, action->dev_id);
-                               if (ret == IRQ_HANDLED)
-                                       status |= action->flags;
-                               retval |= ret;
-                               action = action->next;
-                       } while (action);
-
-                       if (status & IRQF_SAMPLE_RANDOM)
-                               add_interrupt_randomness(irq);
-
-                       local_irq_disable();
-
-                       if (retval != IRQ_HANDLED)
-                               printk(KERN_ERR "ISR for TWL4030 module"
-                                       " irq %d can't handle interrupt\n",
-                                       irq);
-
-                       /*
-                        * Here is where we should call the unmask method, but
-                        * again we won't bother since it is NULL.
-                        */
-               } else
-                       printk(KERN_CRIT "TWL4030 module irq %d has no ISR"
-                                       " but can't be masked!\n", irq);
-       } else
-               printk(KERN_CRIT "TWL4030 module irq %d is disabled but can't"
-                               " be masked!\n", irq);
-}
-
 static unsigned twl4030_irq_base;
 
 static struct completion irq_event;
@@ -611,7 +549,6 @@ static int twl4030_irq_thread(void *data)
        static unsigned i2c_errors;
        const static unsigned max_i2c_errors = 100;
 
-       daemonize("twl4030-irq");
        current->flags |= PF_NOFREEZE;
 
        while (!kthread_should_stop()) {
@@ -691,8 +628,7 @@ static struct task_struct * __init start_twl4030_irq_thread(long irq)
        struct task_struct *thread;
 
        init_completion(&irq_event);
-       thread = kthread_run(twl4030_irq_thread, (void *)irq,
-                            "twl4030 irq %ld", irq);
+       thread = kthread_run(twl4030_irq_thread, (void *)irq, "twl4030-irq");
        if (!thread)
                pr_err("%s: could not create twl4030 irq %ld thread!\n",
                       DRIVER_NAME, irq);
@@ -1126,7 +1062,7 @@ static void twl_init_irq(int irq_num, unsigned irq_base, unsigned irq_end)
        /* install an irq handler for each of the PIH modules */
        for (i = irq_base; i < irq_end; i++) {
                set_irq_chip_and_handler(i, &twl4030_irq_chip,
-                               do_twl4030_module_irq);
+                               handle_simple_irq);
                activate_irq(i);
        }