drm/i915: Fix and clean BDW PCH identification

It seems in the past we have BDW with PCH not been propperly identified
and we force it to be LPT and we were warning !IS_HASWELL on propper identification.

Now that products are out there we are receiveing logs with this incorrect WARN.
And also according to local tests on all production BDW here ULT or HALO we don't
need this force anymore. So let's clean this block for real.

v2: Fix LPT_LP WARNs to avoid wrong warns on BDW_ULT (By Jani).

Reference: https://bugs.freedesktop.org/attachment.cgi?id=110972

Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Xion Zhang <xiong.y.zhang@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

1 files changed, 4 insertions, 10 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 574057cd1d09..7643300828c3 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -462,19 +462,13 @@ void intel_detect_pch(struct drm_device *dev)
                         } else if (id == INTEL_PCH_LPT_DEVICE_ID_TYPE) {
                                 dev_priv->pch_type = PCH_LPT;
                                 DRM_DEBUG_KMS("Found LynxPoint PCH\n");
-                                WARN_ON(!IS_HASWELL(dev));
-                                WARN_ON(IS_HSW_ULT(dev));
-                        } else if (IS_BROADWELL(dev)) {
-                                dev_priv->pch_type = PCH_LPT;
-                                dev_priv->pch_id =
-                                        INTEL_PCH_LPT_LP_DEVICE_ID_TYPE;
-                                DRM_DEBUG_KMS("This is Broadwell, assuming "
-                                              "LynxPoint LP PCH\n");
+                                WARN_ON(!IS_HASWELL(dev) && !IS_BROADWELL(dev));
+                                WARN_ON(IS_HSW_ULT(dev) || IS_BDW_ULT(dev));
                         } else if (id == INTEL_PCH_LPT_LP_DEVICE_ID_TYPE) {
                                 dev_priv->pch_type = PCH_LPT;
                                 DRM_DEBUG_KMS("Found LynxPoint LP PCH\n");
-                                WARN_ON(!IS_HASWELL(dev));
-                                WARN_ON(!IS_HSW_ULT(dev));
+                                WARN_ON(!IS_HASWELL(dev) && !IS_BROADWELL(dev));
+                                WARN_ON(!IS_HSW_ULT(dev) && !IS_BDW_ULT(dev));
                         } else if (id == INTEL_PCH_SPT_DEVICE_ID_TYPE) {
                                 dev_priv->pch_type = PCH_SPT;
                                 DRM_DEBUG_KMS("Found SunrisePoint PCH\n");