drm/i915: account for only one PCH receiver on Haswell

On Haswell, only one pipe can work in FDI mode, so this patch prevents
messing with wrong registers when FDI is being used by non-first pipe. And
to prevent this, we also specify that the VGA can only be used on pipe 0
for now in the crtc_mask value.

Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 16 insertions, 3 deletions

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 7d59d0e852f8..101c4d458c33 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -977,9 +977,14 @@ static void assert_fdi_rx(struct drm_i915_private *dev_priv,
         u32 val;
         bool cur_state;
 
-        reg = FDI_RX_CTL(pipe);
-        val = I915_READ(reg);
-        cur_state = !!(val & FDI_RX_ENABLE);
+        if (IS_HASWELL(dev_priv->dev) && pipe > 0) {
+                        DRM_ERROR("Attempting to enable FDI_RX on Haswell pipe > 0\n");
+                        return;
+        } else {
+                reg = FDI_RX_CTL(pipe);
+                val = I915_READ(reg);
+                cur_state = !!(val & FDI_RX_ENABLE);
+        }
         WARN(cur_state != state,
              "FDI RX state assertion failure (expected %s, current %s)\n",
              state_string(state), state_string(cur_state));
@@ -1012,6 +1017,10 @@ static void assert_fdi_rx_pll_enabled(struct drm_i915_private *dev_priv,
         int reg;
         u32 val;
 
+        if (IS_HASWELL(dev_priv->dev) && pipe > 0) {
+                DRM_ERROR("Attempting to enable FDI on Haswell with pipe > 0\n");
+                return;
+        }
         reg = FDI_RX_CTL(pipe);
         val = I915_READ(reg);
         WARN(!(val & FDI_RX_PLL_ENABLE), "FDI RX PLL assertion failure, should be active but is disabled\n");
@@ -1483,6 +1492,10 @@ static void intel_enable_transcoder(struct drm_i915_private *dev_priv,
         assert_fdi_tx_enabled(dev_priv, pipe);
         assert_fdi_rx_enabled(dev_priv, pipe);
 
+        if (IS_HASWELL(dev_priv->dev) && pipe > 0) {
+                DRM_ERROR("Attempting to enable transcoder on Haswell with pipe > 0\n");
+                return;
+        }
         reg = TRANSCONF(pipe);
         val = I915_READ(reg);
         pipeconf_val = I915_READ(PIPECONF(pipe));