• Imre Deak's avatar
    drm/i915: Init DRM connector polled field early · 289d4180
    Imre Deak authored
    After an HPD IRQ storm on a connector intel_hpd_irq_storm_detect() will
    set the connector's HPD pin state to HPD_MARK_DISABLED and the IRQ gets
    disabled. Subsequently intel_hpd_irq_storm_switch_to_polling() will
    enable polling for these connectors, setting the pin state to
    HPD_DISABLED, but only if the connector's base.polled field is set to
    DRM_CONNECTOR_POLL_HPD. intel_hpd_irq_storm_reenable_work() will
    reenable the IRQ - after 2 minutes -  if the pin state is HPD_DISABLED.
    
    The connectors will be created with their base.polled field set to 0,
    which gets initialized only later in i915_hpd_poll_init_work() (using
    intel_connector::polled). If a storm is detected on a connector after
    it's created and IRQs are enabled on it - by intel_hpd_init() - and
    before its bease.polled field is initialized in the above work, the
    connector's HPD pin will stay in the HPD_MARK_DISABLED state - leaving
    the IRQ disabled indefinitely - and polling will not get enabled on it as
    intended.
    
    I can't see a reason for initializing base.polled in a delayed manner,
    so do this already when creating the connector, to prevent the above
    race condition.
    
    Link: https://patchwork.freedesktop.org/patch/msgid/20240104083008.2715733-2-imre.deak@intel.comReviewed-by: default avatarJouni Högander <jouni.hogander@intel.com>
    Signed-off-by: default avatarImre Deak <imre.deak@intel.com>
    289d4180
intel_dp.c 190 KB