• Sebastian Andrzej Siewior's avatar
    drm/i915/gt: Queue and wait for the irq_work item. · e3b017d5
    Sebastian Andrzej Siewior authored
    
    
    Disabling interrupts and invoking the irq_work function directly breaks
    on PREEMPT_RT.
    PREEMPT_RT does not invoke all irq_work from hardirq context because
    some of the user have spinlock_t locking in the callback function.
    These locks are then turned into a sleeping locks which can not be
    acquired with disabled interrupts.
    
    Using irq_work_queue() has the benefit that the irqwork will be invoked
    in the regular context. In general there is "no" delay between enqueuing
    the callback and its invocation because the interrupt is raised right
    away on architectures which support it (which includes x86).
    
    Use irq_work_queue() + irq_work_sync() instead invoking the callback
    directly.
    Reported-by: default avatarClark Williams <williams@redhat.com>
    Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
    e3b017d5