drm/i915: fix PCH_NOP setting for non-PCH platforms

Setting PCH type to PCH_NOP before checking whether we actually have a
PCH ends up returning true for HAS_PCH_SPLIT() on all non-PCH split
platforms. Fix this by using PCH_NOP only for platforms that actually
have a PCH.

Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180608123330.31003-6-jani.nikula@intel.com

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 9aba419..d258388 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -248,14 +248,6 @@ static void intel_detect_pch(struct drm_i915_private *dev_priv)
 {
        struct pci_dev *pch = NULL;
 
-       /* In all current cases, num_pipes is equivalent to the PCH_NOP setting
-        * (which really amounts to a PCH but no South Display).
-        */
-       if (INTEL_INFO(dev_priv)->num_pipes == 0) {
-               dev_priv->pch_type = PCH_NOP;
-               return;
-       }
-
        /*
         * The reason to probe ISA bridge instead of Dev31:Fun0 is to
         * make graphics device passthrough work easy for VMM, that only
@@ -295,6 +287,17 @@ static void intel_detect_pch(struct drm_i915_private *dev_priv)
                        break;
                }
        }
+
+       /*
+        * Use PCH_NOP (PCH but no South Display) for PCH platforms without
+        * display.
+        */
+       if (pch && INTEL_INFO(dev_priv)->num_pipes == 0) {
+               DRM_DEBUG_KMS("Display disabled, reverting to NOP PCH\n");
+               dev_priv->pch_type = PCH_NOP;
+               dev_priv->pch_id = 0;
+       }
+
        if (!pch)
                DRM_DEBUG_KMS("No PCH found.\n");