[Intel-gfx] [PATCH 1/4] drm/i915: Move pipe enable/disable tracepoints to intel_crtc_vblank_{on, off}()

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

On platforms/outputs without a working frame counter we rely
on the vblank code to cook up the frame counter from the timestamps.
That requires that vblank support is enabled. Thus we need to
move the pipe enable/disable tracepoints to the other side
of the drm_vblank_{on,off}() calls. There shouldn't really be
much happening between these old and new call sites so the
tracepoints should still provide reasonable data.

The alternative would be to give up on having the frame counter
values in the trace which would render the tracepoints more or
less pointless.

Reported-by: Steven Rostedt <rostedt at goodmis.org>
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_crtc.c    | 16 ++++++++++++++++
 drivers/gpu/drm/i915/display/intel_display.c |  8 +-------
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_crtc.c b/drivers/gpu/drm/i915/display/intel_crtc.c
index 88b44ac50aae..fd8a66cece80 100644
--- a/drivers/gpu/drm/i915/display/intel_crtc.c
+++ b/drivers/gpu/drm/i915/display/intel_crtc.c
@@ -28,6 +28,8 @@
 #include "i9xx_plane.h"
 #include "skl_universal_plane.h"
 
+#include "i915_trace.h"
+
 static void assert_vblank_disabled(struct drm_crtc *crtc)
 {
 	if (I915_STATE_WARN_ON(drm_crtc_vblank_get(crtc) == 0))
@@ -84,12 +86,26 @@ void intel_crtc_vblank_on(const struct intel_crtc_state *crtc_state)
 	drm_crtc_set_max_vblank_count(&crtc->base,
 				      intel_crtc_max_vblank_count(crtc_state));
 	drm_crtc_vblank_on(&crtc->base);
+
+	/*
+	 * Should really happen exactly when we enable the pipe
+	 * but we want the frame counters in the trace, and that
+	 * requires vblank support on some platforms/outputs.
+	 */
+	trace_intel_pipe_enable(crtc);
 }
 
 void intel_crtc_vblank_off(const struct intel_crtc_state *crtc_state)
 {
 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
 
+	/*
+	 * Should really happen exactly when we disable the pipe
+	 * but we want the frame counters in the trace, and that
+	 * requires vblank support on some platforms/outputs.
+	 */
+	trace_intel_pipe_disable(crtc);
+
 	drm_crtc_vblank_off(&crtc->base);
 	assert_vblank_disabled(&crtc->base);
 }
diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index b346f6ceb4a2..16b5cb73ddac 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -794,8 +794,6 @@ void intel_enable_pipe(const struct intel_crtc_state *new_crtc_state)
 		/* FIXME: assert CPU port conditions for SNB+ */
 	}
 
-	trace_intel_pipe_enable(crtc);
-
 	reg = PIPECONF(cpu_transcoder);
 	val = intel_de_read(dev_priv, reg);
 	if (val & PIPECONF_ENABLE) {
@@ -835,8 +833,6 @@ void intel_disable_pipe(const struct intel_crtc_state *old_crtc_state)
 	 */
 	assert_planes_disabled(crtc);
 
-	trace_intel_pipe_disable(crtc);
-
 	reg = PIPECONF(cpu_transcoder);
 	val = intel_de_read(dev_priv, reg);
 	if ((val & PIPECONF_ENABLE) == 0)
@@ -4023,10 +4019,8 @@ static void hsw_crtc_enable(struct intel_atomic_state *state,
 	if (INTEL_GEN(dev_priv) >= 11)
 		icl_pipe_mbus_enable(crtc);
 
-	if (new_crtc_state->bigjoiner_slave) {
-		trace_intel_pipe_enable(crtc);
+	if (new_crtc_state->bigjoiner_slave)
 		intel_crtc_vblank_on(new_crtc_state);
-	}
 
 	intel_encoders_enable(state, crtc);
 
-- 
2.26.2