[Intel-gfx] [PATCH 2/8] drm/i915: hw state readout support for pipe_config->fdi_lanes

[Daniel Vetter]

---
 drivers/gpu/drm/i915/intel_display.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 8f5b7da..c75d429 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -5493,9 +5493,13 @@ static bool ironlake_get_pipe_config(struct intel_crtc *crtc,
 	if (!(tmp & PIPECONF_ENABLE))
 		return false;
 
-	if (I915_READ(TRANSCONF(crtc->pipe)) & TRANS_ENABLE)
+	if (I915_READ(TRANSCONF(crtc->pipe)) & TRANS_ENABLE) {
 		pipe_config->has_pch_encoder = true;
 
+		tmp = I915_READ(FDI_RX_CTL(crtc->pipe));
+		pipe_config->fdi_lanes = ((tmp >> 19) & 0x3) + 1;
+	}
+
 	return true;
 }
 
@@ -5622,9 +5626,13 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
 	 */
 	tmp = I915_READ(TRANS_DDI_FUNC_CTL(crtc->pipe));
 	if ((tmp & TRANS_DDI_PORT_MASK) == TRANS_DDI_SELECT_PORT(PORT_E) &&
-	    I915_READ(TRANSCONF(PIPE_A)) & TRANS_ENABLE)
+	    I915_READ(TRANSCONF(PIPE_A)) & TRANS_ENABLE) {
 		pipe_config->has_pch_encoder = true;
 
+		tmp = I915_READ(FDI_RX_CTL(PIPE_A));
+		pipe_config->fdi_lanes = ((tmp >> 19) & 0x3) + 1;
+	}
+
 
 	return true;
 }
@@ -7583,6 +7591,14 @@ intel_pipe_config_compare(struct intel_crtc_config *current_config,
 		return false;
 	}
 
+	if (current_config->fdi_lanes != pipe_config->fdi_lanes) {
+		DRM_ERROR("mismatch in fdi_lanes "
+			  "(expected %i, found %i)\n",
+			  current_config->fdi_lanes,
+			  pipe_config->fdi_lanes);
+		return false;
+	}
+
 	return true;
 }
 
-- 
1.7.11.4