drm/i915/ibx: Ensure the HW is powered during PLL HW 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: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455296121-4742-4-git-send-email-imre.deak@intel.com
(cherry picked from commit 12fda3876d)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
This commit is contained in:
Imre Deak 2016-02-12 18:55:12 +02:00 committed by Jani Nikula
parent 9fb84d5a92
commit 013ef6cfc4

View File

@ -13659,7 +13659,7 @@ static bool ibx_pch_dpll_get_hw_state(struct drm_i915_private *dev_priv,
{
uint32_t val;
if (!intel_display_power_is_enabled(dev_priv, POWER_DOMAIN_PLLS))
if (!intel_display_power_get_if_enabled(dev_priv, POWER_DOMAIN_PLLS))
return false;
val = I915_READ(PCH_DPLL(pll->id));
@ -13667,6 +13667,8 @@ static bool ibx_pch_dpll_get_hw_state(struct drm_i915_private *dev_priv,
hw_state->fp0 = I915_READ(PCH_FP0(pll->id));
hw_state->fp1 = I915_READ(PCH_FP1(pll->id));
intel_display_power_put(dev_priv, POWER_DOMAIN_PLLS);
return val & DPLL_VCO_ENABLE;
}