1 files changed, 31 insertions, 15 deletions

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 89a3ea82569b..585f6381f8e4 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -565,8 +565,8 @@ int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
                  * IRQF_TRIGGER_* but the PIC does not support multiple
                  * flow-types?
                  */
-                pr_debug("No set_type function for IRQ %d (%s)\n", irq,
-                                chip ? (chip->name ? : "unknown") : "unknown");
+                pr_debug("genirq: No set_type function for IRQ %d (%s)\n", irq,
+                         chip ? (chip->name ? : "unknown") : "unknown");
                 return 0;
         }
 
@@ -600,7 +600,7 @@ int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
                 ret = 0;
                 break;
         default:
-                pr_err("setting trigger mode %lu for irq %u failed (%pF)\n",
+                pr_err("genirq: Setting trigger mode %lu for irq %u failed (%pF)\n",
                        flags, irq, chip->irq_set_type);
         }
         if (unmask)
@@ -837,8 +837,7 @@ void exit_irq_thread(void)
 
         action = kthread_data(tsk);
 
-        printk(KERN_ERR
-               "exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
+        pr_err("genirq: exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n",
                tsk->comm ? tsk->comm : "", tsk->pid, action->irq);
 
         desc = irq_to_desc(action->irq);
@@ -878,7 +877,6 @@ static int
 __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 {
         struct irqaction *old, **old_ptr;
-        const char *old_name = NULL;
         unsigned long flags, thread_mask = 0;
         int ret, nested, shared = 0;
         cpumask_var_t mask;
@@ -972,10 +970,8 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
                  */
                 if (!((old->flags & new->flags) & IRQF_SHARED) ||
                     ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) ||
-                    ((old->flags ^ new->flags) & IRQF_ONESHOT)) {
-                        old_name = old->name;
+                    ((old->flags ^ new->flags) & IRQF_ONESHOT))
                         goto mismatch;
-                }
 
                 /* All handlers must agree on per-cpuness */
                 if ((old->flags & IRQF_PERCPU) !=
@@ -1031,6 +1027,27 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
                  * all existing action->thread_mask bits.
                  */
                 new->thread_mask = 1 << ffz(thread_mask);
+
+        } else if (new->handler == irq_default_primary_handler) {
+                /*
+                 * The interrupt was requested with handler = NULL, so
+                 * we use the default primary handler for it. But it
+                 * does not have the oneshot flag set. In combination
+                 * with level interrupts this is deadly, because the
+                 * default primary handler just wakes the thread, then
+                 * the irq lines is reenabled, but the device still
+                 * has the level irq asserted. Rinse and repeat....
+                 *
+                 * While this works for edge type interrupts, we play
+                 * it safe and reject unconditionally because we can't
+                 * say for sure which type this interrupt really
+                 * has. The type flags are unreliable as the
+                 * underlying chip implementation can override them.
+                 */
+                pr_err("genirq: Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n",
+                       irq);
+                ret = -EINVAL;
+                goto out_mask;
         }
 
         if (!shared) {
@@ -1078,7 +1095,7 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 
                 if (nmsk != omsk)
                         /* hope the handler works with current  trigger mode */
-                        pr_warning("IRQ %d uses trigger mode %u; requested %u\n",
+                        pr_warning("genirq: irq %d uses trigger mode %u; requested %u\n",
                                    irq, nmsk, omsk);
         }
 
@@ -1115,14 +1132,13 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
         return 0;
 
 mismatch:
-#ifdef CONFIG_DEBUG_SHIRQ
         if (!(new->flags & IRQF_PROBE_SHARED)) {
-                printk(KERN_ERR "IRQ handler type mismatch for IRQ %d\n", irq);
-                if (old_name)
-                        printk(KERN_ERR "current handler: %s\n", old_name);
+                pr_err("genirq: Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n",
+                       irq, new->flags, new->name, old->flags, old->name);
+#ifdef CONFIG_DEBUG_SHIRQ
                 dump_stack();
-        }
 #endif
+        }
         ret = -EBUSY;
 
 out_mask: