• Tony Lindgren's avatar
    PM / wakeirq: Fix dedicated wakeirq for drivers not using autosuspend · bed57030
    Tony Lindgren authored
    I noticed some wakeirq flakeyness with consumer drivers not using
    autosuspend. For drivers not using autosuspend, the wakeirq may never
    get unmasked in rpm_suspend() because of irq desc->depth.
    
    We are configuring dedicated wakeirqs to start with IRQ_NOAUTOEN as we
    naturally don't want them running until rpm_suspend() is called.
    
    However, when a consumer driver initially calls pm_runtime_get(), we
    now wrongly start with disable_irq_nosync() call on the dedicated
    wakeirq that is disabled to start with.
    
    This causes desc->depth to toggle between 1 and 2 instead of the usual
    0 and 1. This can prevent enable_irq() from unmasking the wakeirq as
    that only happens at desc->depth 1.
    
    This does not necessarily show up with drivers using autosuspend as
    there is time for disable_irq_nosync() before rpm_suspend() gets called
    after the autosuspend timeout.
    
    Let's fix the issue by adding wirq->status that lazily gets set on
    the first rpm_suspend(). We also need PM runtime core private functions
    for dev_pm_enable_wake_irq_check() and dev_pm_disable_wake_irq_check()
    so we can enable the dedicated wakeirq on the first rpm_suspend().
    
    While at it, let's also fix the comments for dev_pm_enable_wake_irq()
    and dev_pm_disable_wake_irq(). Those can still be used by the consumer
    drivers as needed because the IRQ core manages the interrupt usecount
    for us.
    
    Fixes: 4990d4fe (PM / Wakeirq: Add automated device wake IRQ handling)
    Signed-off-by: default avatarTony Lindgren <tony@atomide.com>
    Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
    bed57030
wakeirq.c 8.68 KB