From 380bdff2d05b498227c80caedd125e8cfcdba00d Mon Sep 17 00:00:00 2001 From: Imre Deak Date: Fri, 12 Feb 2016 18:55:21 +0200 Subject: [PATCH] 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 Reviewed-by: Daniel Vetter 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 --- drivers/gpu/drm/i915/intel_lvds.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c index 0da0240caf81..bc04d8d29acb 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, -- 2.30.2