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 4d80003023)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
This commit is contained in:
Imre Deak 2016-02-16 18:56:46 +02:00 committed by Jani Nikula
parent 380bdff2d0
commit 53188eb401
1 changed files with 6 additions and 1 deletions

View File

@ -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);
}
}