drm/i915: Check for FIFO underruns after modeset on IVB/HSW and CPT/PPT

Due to the shared error interrupt on IVB/HSW and CPT/PPT we may not
always get an interrupt on a FIFO underrun. But we can always do an
explicit check (like we do on GMCH platforms that have no underrun
interrupt).

v2: Drop stale kerneldoc for i9xx_check_fifo_underruns() (Daniel)

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1446225741-11070-1-git-send-email-ville.syrjala@linux.intel.com
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 0f8fd14..d456774 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -965,7 +965,8 @@
 					 enum pipe pipe);
 void intel_pch_fifo_underrun_irq_handler(struct drm_i915_private *dev_priv,
 					 enum transcoder pch_transcoder);
-void i9xx_check_fifo_underruns(struct drm_i915_private *dev_priv);
+void intel_check_cpu_fifo_underruns(struct drm_i915_private *dev_priv);
+void intel_check_pch_fifo_underruns(struct drm_i915_private *dev_priv);
 
 /* i915_irq.c */
 void gen5_enable_gt_irq(struct drm_i915_private *dev_priv, uint32_t mask);