Spurious irq will be disabled and then polled through mod_timer in
interrupt context. While mod_timer has a common spin_lock operation
thus will cause an error: BUG: sleeping function called from invalid
context.
Move the mod_timer into simple work queue to fix it.
Signed-off-by: Zhang Xiao <xiao.zhang@xxxxxxxxxxxxx>
---
kernel/irq/spurious.c | 39 +++++++++++++++++++++++++++++++++++++++
1 file changed, 39 insertions(+)
diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index 903a69c..0ce2a38 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -24,6 +24,36 @@ static DEFINE_TIMER(poll_spurious_irq_timer, poll_spurious_irqs, 0, 0);
static int irq_poll_cpu;
static atomic_t irq_poll_active;
+#ifdef CONFIG_PREEMPT_RT_FULL
+#include <linux/work-simple.h>
+
+static bool mod_timer_work_ready __read_mostly;
+static struct swork_event mod_timer_work;
+
+static void __mod_timer_work(struct swork_event *event)
+{
+ mod_timer(&poll_spurious_irq_timer,
+ jiffies + POLL_SPURIOUS_IRQ_INTERVAL);
+}
+
+static int __init mod_timer_work_init(void)
+{
+ int err;
+
+ err = swork_get();
+ if(err) {
+ printk(KERN_ERR "mod_timer work init failed.\n");
+ return err;
+ }
+
+ INIT_SWORK(&mod_timer_work, __mod_timer_work);
+ mod_timer_work_ready = true;
+ return 0;
+}
+
+early_initcall(mod_timer_work_init);
+#endif /* CONFIG_PREEMPT_RT_FULL */
+
/*
* We wait here for a poller to finish.
*
@@ -422,8 +452,17 @@ void note_interrupt(unsigned int irq, struct irq_desc *desc,
desc->depth++;
irq_disable(desc);
+#ifdef CONFIG_PREEMPT_RT_FULL
+ /*
+ * Avoid calling mod_timer directly in interrupt
+ * contex here. Let simple workqueue do it.
+ */
+ if(mod_timer_work_ready)
+ swork_queue(&mod_timer_work);
+#else
mod_timer(&poll_spurious_irq_timer,
jiffies + POLL_SPURIOUS_IRQ_INTERVAL);
+#endif /* CONFIG_PREEMPT_RT_FULL */
}
desc->irqs_unhandled = 0;
}
--
1.9.1
--
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