drm/i915: check whether the pch is the soulmate of the cpu

We don't really support fancy north display/pch combinations, so
put a big yelling WARN_ON in there. It /should/ be impossible, but
alas, the rumours don't stop (mostly due to really early silicon
sometimes using older PCHs).

v2: Fixup the logic fumble noticed by Paulo Zanoni. I should actually
try to test run the patch next time around ...

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/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 4238853..4be4841 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -416,19 +416,23 @@ void intel_detect_pch(struct drm_device *dev)
                                dev_priv->pch_type = PCH_IBX;
                                dev_priv->num_pch_pll = 2;
                                DRM_DEBUG_KMS("Found Ibex Peak PCH\n");
+                               WARN_ON(!IS_GEN5(dev));
                        } else if (id == INTEL_PCH_CPT_DEVICE_ID_TYPE) {
                                dev_priv->pch_type = PCH_CPT;
                                dev_priv->num_pch_pll = 2;
                                DRM_DEBUG_KMS("Found CougarPoint PCH\n");
+                               WARN_ON(!(IS_GEN6(dev) || IS_IVYBRIDGE(dev)));
                        } else if (id == INTEL_PCH_PPT_DEVICE_ID_TYPE) {
                                /* PantherPoint is CPT compatible */
                                dev_priv->pch_type = PCH_CPT;
                                dev_priv->num_pch_pll = 2;
                                DRM_DEBUG_KMS("Found PatherPoint PCH\n");
+                               WARN_ON(!(IS_GEN6(dev) || IS_IVYBRIDGE(dev)));
                        } else if (id == INTEL_PCH_LPT_DEVICE_ID_TYPE) {
                                dev_priv->pch_type = PCH_LPT;
                                dev_priv->num_pch_pll = 0;
                                DRM_DEBUG_KMS("Found LynxPoint PCH\n");
+                               WARN_ON(!IS_HASWELL(dev));
                        }
                        BUG_ON(dev_priv->num_pch_pll > I915_NUM_PLLS);
                }