drm/i915: Add cxsr toggle tracepoint

Add a tracepoint for observing changes in the cxsr state. The tracepoint
will dump out the frame and scanline counters for each pipe so that the
information can be compared with eg. plane update tracepoints.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170302171508.1666-18-ville.syrjala@linux.intel.com

drivers/gpu/drm/i915/i915_trace.h

@@ -16,6 +16,36 @@
 
 /* watermark/fifo updates */
 
+TRACE_EVENT(intel_memory_cxsr,
+	    TP_PROTO(struct drm_i915_private *dev_priv, bool old, bool new),
+	    TP_ARGS(dev_priv, old, new),
+
+	    TP_STRUCT__entry(
+			     __array(u32, frame, 3)
+			     __array(u32, scanline, 3)
+			     __field(bool, old)
+			     __field(bool, new)
+			     ),
+
+	    TP_fast_assign(
+			   enum pipe pipe;
+			   for_each_pipe(dev_priv, pipe) {
+				   __entry->frame[pipe] =
+					   dev_priv->drm.driver->get_vblank_counter(&dev_priv->drm, pipe);
+				   __entry->scanline[pipe] =
+					   intel_get_crtc_scanline(intel_get_crtc_for_pipe(dev_priv, pipe));
+			   }
+			   __entry->old = old;
+			   __entry->new = new;
+			   ),
+
+	    TP_printk("%s->%s, pipe A: frame=%u, scanline=%u, pipe B: frame=%u, scanline=%u, pipe C: frame=%u, scanline=%u",
+		      onoff(__entry->old), onoff(__entry->new),
+		      __entry->frame[PIPE_A], __entry->scanline[PIPE_A],
+		      __entry->frame[PIPE_B], __entry->scanline[PIPE_B],
+		      __entry->frame[PIPE_C], __entry->scanline[PIPE_C])
+);
+
 TRACE_EVENT(vlv_wm,
 	    TP_PROTO(struct intel_crtc *crtc, const struct vlv_wm_values *wm),
 	    TP_ARGS(crtc, wm),

drivers/gpu/drm/i915/intel_pm.c

@@ -377,6 +377,8 @@ static bool _intel_set_memory_cxsr(struct drm_i915_private *dev_priv, bool enabl
 		return false;
 	}
 
+	trace_intel_memory_cxsr(dev_priv, was_enabled, enable);
+
 	DRM_DEBUG_KMS("memory self-refresh is %s (was %s)\n",
 		      enableddisabled(enable),
 		      enableddisabled(was_enabled));