Understanding kernel message 'nobody cared (try booting with the "irqpoll" option)'

Question

I'm trying to understand the meaning of the following message:

irq N:nobody cared (try booting with the "irqpoll" option)

Does this mean the IRQ handler not processing the response even it has gotten the interrupt? Or that the scheduler failed to call an irq handler?

In what condition is this happening?

Answer 1

it means that either no handler is registered for that irq or the one that is returned status indicating that the irq was not for him (from hardware he is supporting) in case of shared interrupts probably a faulty HW/FW or buggy driver

Answer 2

Ideally, the above message should be followed by a stack trace, which should help you determine which subsystem is causing the issue. This message means the interrupt handler got stuck due to a overhead, and did not return thus causing the system to disable IRQ#X. This is seen in cases of a buggy firmware.

The irqpoll option needs to be added to grub.conf, which means, when an interrupt is not handled, search all known interrupt handlers for the appropriate handlers and also check all handlers on each timer interrupt. This is sometimes useful to get systems with broken firmware running. The kernel command line in grub.conf should look like the following:

kernel /vmlinuz-version ro root=/dev/sda1 quiet irqpoll