drm/i915: Keep the connector polled state disabled after storm

If an HPD IRQ storm is detected on a connector during driver loading or
system suspend/resume - disabling the IRQ and switching to polling - the
polling may get disabled too early - before the intended 2 minute
HPD_STORM_REENABLE_DELAY - with the HPD IRQ staying disabled for this
duration. One such sequence is:

Thread#1                                   Thread#2
intel_display_driver_probe()->
  intel_hpd_init()->
    (HPD IRQ gets enabled)
  .                                        intel_hpd_irq_handler()->
  .                                          intel_hpd_irq_storm_detect()
  .                                            intel_hpd_irq_setup()->
  .                                              (HPD IRQ gets disabled)
  .                                         queue_delayed_work(hotplug.hotplug_work)
  .                                         ...
  .                                         i915_hotplug_work_func()->
  .                                           intel_hpd_irq_storm_switch_to_polling()->
  .                                             (polling enabled)
  .
  intel_hpd_poll_disable()->
    queue_work(hotplug.poll_init_work)
  ...
  i915_hpd_poll_init_work()->
    (polling gets disabled,
     HPD IRQ is still disabled)
  ...

  (Connector is neither polled or
   detected via HPD IRQs for 2 minutes)

  intel_hpd_irq_storm_reenable_work()->
    (HPD IRQ gets enabled)

To avoid the above 2 minute state without either polling or enabled HPD
IRQ, leave the connector's polling mode unchanged in
i915_hpd_poll_init_work() if its HPD IRQ got disabled after an IRQ storm
indicated by the connector's HPD_DISABLED pin state.

Link: https://patchwork.freedesktop.org/patch/msgid/20240104083008.2715733-3-imre.deak@intel.com
Reviewed-by: Jouni Högander <jouni.hogander@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>

0 files changed, 0 insertions, 0 deletions