drm/i915: rip out dp port enabling cludges^Wchecks

These have been added because dp links are fiddle things and don't
like it when we try to re-train an enabled output (or disable a
disabled output harder). And because the crtc helper code is
ridiculously bad add tracking the modeset state.

But with the new code in place it is simply a bug to disable a disabled
encoder or to enable an enabled encoder again. Hence convert these to
WARNs (and bail out for safety), but flatten all conditionals in the
code itself.

Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 0f84800..8a70df0 100644 (file)
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1333,15 +1333,15 @@ static void intel_enable_dp(struct intel_encoder *encoder)
        struct drm_i915_private *dev_priv = dev->dev_private;
        uint32_t dp_reg = I915_READ(intel_dp->output_reg);
 
+       if (WARN_ON(dp_reg & DP_PORT_EN))
+               return;
+
        ironlake_edp_panel_vdd_on(intel_dp);
        intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON);
-       if (!(dp_reg & DP_PORT_EN)) {
-               intel_dp_start_link_train(intel_dp);
-               ironlake_edp_panel_on(intel_dp);
-               ironlake_edp_panel_vdd_off(intel_dp, true);
-               intel_dp_complete_link_train(intel_dp);
-       } else
-               ironlake_edp_panel_vdd_off(intel_dp, false);
+       intel_dp_start_link_train(intel_dp);
+       ironlake_edp_panel_on(intel_dp);
+       ironlake_edp_panel_vdd_off(intel_dp, true);
+       intel_dp_complete_link_train(intel_dp);
        ironlake_edp_backlight_on(intel_dp);
 }
 
@@ -1900,7 +1900,7 @@ intel_dp_link_down(struct intel_dp *intel_dp)
        struct drm_i915_private *dev_priv = dev->dev_private;
        uint32_t DP = intel_dp->DP;
 
-       if ((I915_READ(intel_dp->output_reg) & DP_PORT_EN) == 0)
+       if (WARN_ON((I915_READ(intel_dp->output_reg) & DP_PORT_EN) == 0))
                return;
 
        DRM_DEBUG_KMS("\n");