Commits
Imre Deak committed 5af9a454769
drm/i915: Add helper to get a display power ref if it was already enabled We have many places in the code where we check if a given display power domain is enabled and if so access registers backed by this power domain. We assumed that some modeset lock will prevent the power reference from vanishing in the middle of the HW access, but this assumption doesn't always hold. In such cases we get either the wakeref not held, or an unclaimed register access error message. To fix this in a future-proof way that's independent of other locks wrap any such access with a get_ref_if_enabled()/put_ref() pair. Kudos to Ville and Joonas for the ideas of this new interface. v2: - init the power_domains ptr when declaring it everywhere (Joonas) v3: - don't report the device to be powered if runtime PM is disabled CC: Mika Kuoppala <mika.kuoppala@intel.com> CC: Chris Wilson <chris@chris-wilson.co.uk> CC: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> CC: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1455711462-7442-1-git-send-email-imre.deak@intel.com (cherry picked from commit 09731280028ce03e6a27e1998137f1775a2839f3) Signed-off-by: Jani Nikula <jani.nikula@intel.com>