drm/nouveau: Don't enabling polling twice on runtime resume

As it turns out, on cards that actually have CRTCs on them we're already
calling drm_kms_helper_poll_enable(drm_dev) from
nouveau_display_resume() before we call it in
nouveau_pmops_runtime_resume(). This leads us to accidentally trying to
enable polling twice, which results in a potential deadlock between the
RPM locks and drm_dev->mode_config.mutex if we end up trying to enable
polling the second time while output_poll_execute is running and holding
the mode_config lock. As such, make sure we only enable polling in
nouveau_pmops_runtime_resume() if we need to.

This fixes hangs observed on the ThinkPad W541

Signed-off-by: Lyude <[email protected]>
Cc: Hans de Goede <[email protected]>
Cc: Kilian Singer <[email protected]>
Cc: Lukas Wunner <[email protected]>
Cc: David Airlie <[email protected]>
Signed-off-by: Dave Airlie <[email protected]>

0 files changed, 0 insertions, 0 deletions