Commit 53188eb4 authored Feb 16, 2016 by Imre Deak Committed by Jani Nikula Feb 22, 2016

drm/i915/skl: Ensure HW is powered during DDB HW state readout



The assumption when adding the intel_display_power_is_enabled() checks
was that if it returns success the power can't be turned off afterwards
during the HW access, which is guaranteed by modeset locks. This isn't
always true, so make sure we hold a dedicated reference for the time of
the access.

Spotted-by: Mika Kuoppala <mika.kuoppala@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93441


CC: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455719489-3008-1-git-send-email-imre.deak@intel.com


(cherry picked from commit 4d800030)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

parent 380bdff2

drivers/gpu/drm/i915/intel_pm.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -2829,7 +2829,10 @@ void skl_ddb_get_hw_state(struct drm_i915_private *dev_priv,
		memset(ddb, 0, sizeof(*ddb));

		for_each_pipe(dev_priv, pipe) {
		if (!intel_display_power_is_enabled(dev_priv, POWER_DOMAIN_PIPE(pipe)))
		enum intel_display_power_domain power_domain;

		power_domain = POWER_DOMAIN_PIPE(pipe);
		if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
		continue;

		for_each_plane(dev_priv, pipe, plane) {
		@@ -2841,6 +2844,8 @@ void skl_ddb_get_hw_state(struct drm_i915_private *dev_priv,
		val = I915_READ(CUR_BUF_CFG(pipe));
		skl_ddb_entry_init_from_hw(&ddb->plane[pipe][PLANE_CURSOR],
		val);

		intel_display_power_put(dev_priv, power_domain);
		}
		}