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authorImre Deak <imre.deak@intel.com>2016-02-12 16:55:21 (GMT)
committerJani Nikula <jani.nikula@intel.com>2016-02-22 15:44:40 (GMT)
commit380bdff2d05b498227c80caedd125e8cfcdba00d (patch)
tree022d9c34fe50bdbc815c22494c025b34b16aa6d5 /drivers
parent31feb61a688bd4b1c1cb66cc24d931ee77826d93 (diff)
downloadlinux-380bdff2d05b498227c80caedd125e8cfcdba00d.tar.xz
drm/i915/lvds: Ensure the HW is powered during 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. Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: http://patchwork.freedesktop.org/patch/msgid/1455296121-4742-13-git-send-email-imre.deak@intel.com (cherry picked from commit ecb2448218acf23c401434c26be256147833b221) Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/gpu/drm/i915/intel_lvds.c14
1 files changed, 11 insertions, 3 deletions
diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index 0da0240..bc04d8d 100644
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -75,22 +75,30 @@ static bool intel_lvds_get_hw_state(struct intel_encoder *encoder,
struct intel_lvds_encoder *lvds_encoder = to_lvds_encoder(&encoder->base);
enum intel_display_power_domain power_domain;
u32 tmp;
+ bool ret;
power_domain = intel_display_port_power_domain(encoder);
- if (!intel_display_power_is_enabled(dev_priv, power_domain))
+ if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
return false;
+ ret = false;
+
tmp = I915_READ(lvds_encoder->reg);
if (!(tmp & LVDS_PORT_EN))
- return false;
+ goto out;
if (HAS_PCH_CPT(dev))
*pipe = PORT_TO_PIPE_CPT(tmp);
else
*pipe = PORT_TO_PIPE(tmp);
- return true;
+ ret = true;
+
+out:
+ intel_display_power_put(dev_priv, power_domain);
+
+ return ret;
}
static void intel_lvds_get_config(struct intel_encoder *encoder,