drm/i915: add LPT PCH checks

Avoid bogus asserts and PCH PLL accesses on Lynx Point.

Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index bb049a178632f168facf0e60c6c06f6caf61e819..c8f85de137e307c2764ebb4f120eb842286fa9f8 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -916,6 +916,11 @@ static void assert_pch_pll(struct drm_i915_private *dev_priv,
        u32 val;
        bool cur_state;
 
+       if (HAS_PCH_LPT(dev_priv->dev)) {
+               DRM_DEBUG_DRIVER("LPT detected: skipping PCH PLL test\n");
+               return;
+       }
+
        if (!intel_crtc->pch_pll) {
                WARN(1, "asserting PCH PLL enabled with no PLL\n");
                return;
@@ -1101,6 +1106,11 @@ static void assert_pch_refclk_enabled(struct drm_i915_private *dev_priv)
        u32 val;
        bool enabled;
 
+       if (HAS_PCH_LPT(dev_priv->dev)) {
+               DRM_DEBUG_DRIVER("LPT does not has PCH refclk, skipping check\n");
+               return;
+       }
+
        val = I915_READ(PCH_DREF_CONTROL);
        enabled = !!(val & (DREF_SSC_SOURCE_MASK | DREF_NONSPREAD_SOURCE_MASK |
                            DREF_SUPERSPREAD_SOURCE_MASK));
@@ -4406,8 +4416,12 @@ static int ironlake_crtc_mode_set(struct drm_crtc *crtc,
        DRM_DEBUG_KMS("Mode for pipe %d:\n", pipe);
        drm_mode_debug_printmodeline(mode);
 
-       /* CPU eDP is the only output that doesn't need a PCH PLL of its own */
-       if (!is_cpu_edp) {
+       /* CPU eDP is the only output that doesn't need a PCH PLL of its own on
+        * pre-Haswell/LPT generation */
+       if (HAS_PCH_LPT(dev)) {
+               DRM_DEBUG_KMS("LPT detected: no PLL for pipe %d necessary\n",
+                               pipe);
+       } else if (!is_cpu_edp) {
                struct intel_pch_pll *pll;
 
                pll = intel_get_pch_pll(intel_crtc, dpll, fp);