[PATCH 4/4] drm/i915/display: Cover all possible pipes in TP_printk()

[Gustavo Sousa <gustavo.sousa@intel.com>]

Tracepoints that display frame and scanline counters for all pipes were
added with commit 1489bba82433 ("drm/i915: Add cxsr toggle tracepoint")
and commit 0b2599a43ca9 ("drm/i915: Add pipe enable/disable
tracepoints"). At that time, we only had pipes A, B and C. Now that we
can also have pipe D, the TP_printk() calls are missing it.

As a quick and dirty fix for that, let's define two common macros to be
used for the format and values respectively, and also ensure we raise a
build bug if more pipes are added to enum pipe.

In the future, we should probably have a way of printing information for
available pipes only.

Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com>
---
 .../drm/i915/display/intel_display_trace.h    | 43 +++++++++++++------
 1 file changed, 29 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display_trace.h b/drivers/gpu/drm/i915/display/intel_display_trace.h
index 759b985c84a9..2ce66dffdfa5 100644
--- a/drivers/gpu/drm/i915/display/intel_display_trace.h
+++ b/drivers/gpu/drm/i915/display/intel_display_trace.h
@@ -30,6 +30,29 @@
 #define _TRACE_PIPE_A	0
 #define _TRACE_PIPE_B	1
 #define _TRACE_PIPE_C	2
+#define _TRACE_PIPE_D	3
+
+/*
+ * FIXME: Several TP_printk() calls below display frame and scanline numbers for
+ * all possible pipes (regardless of whether they are available) and that is
+ * done with a constant format string. A better approach would be to generate
+ * that info dynamically based on available pipes, but, while we do not have
+ * that implemented yet, let's assert that the constant format string indeed
+ * covers all possible pipes.
+ */
+static_assert(I915_MAX_PIPES - 1 == _TRACE_PIPE_D);
+
+#define _PIPES_FRAME_AND_SCANLINE_FMT		\
+	"pipe A: frame=%u, scanline=%u"		\
+	", pipe B: frame=%u, scanline=%u"	\
+	", pipe C: frame=%u, scanline=%u"	\
+	", pipe D: frame=%u, scanline=%u"
+
+#define _PIPES_FRAME_AND_SCANLINE_VALUES					\
+	__entry->frame[_TRACE_PIPE_A], __entry->scanline[_TRACE_PIPE_A]		\
+	, __entry->frame[_TRACE_PIPE_B], __entry->scanline[_TRACE_PIPE_B]	\
+	, __entry->frame[_TRACE_PIPE_C], __entry->scanline[_TRACE_PIPE_C]	\
+	, __entry->frame[_TRACE_PIPE_D], __entry->scanline[_TRACE_PIPE_D]
 
 TRACE_EVENT(intel_pipe_enable,
 	    TP_PROTO(struct intel_crtc *crtc),
@@ -52,11 +75,8 @@ TRACE_EVENT(intel_pipe_enable,
 			   __entry->pipe_name = pipe_name(crtc->pipe);
 			   ),
 
-	    TP_printk("dev %s, pipe %c enable, pipe A: frame=%u, scanline=%u, pipe B: frame=%u, scanline=%u, pipe C: frame=%u, scanline=%u",
-		      __get_str(dev), __entry->pipe_name,
-		      __entry->frame[_TRACE_PIPE_A], __entry->scanline[_TRACE_PIPE_A],
-		      __entry->frame[_TRACE_PIPE_B], __entry->scanline[_TRACE_PIPE_B],
-		      __entry->frame[_TRACE_PIPE_C], __entry->scanline[_TRACE_PIPE_C])
+	    TP_printk("dev %s, pipe %c enable, " _PIPES_FRAME_AND_SCANLINE_FMT,
+		      __get_str(dev), __entry->pipe_name, _PIPES_FRAME_AND_SCANLINE_VALUES)
 );
 
 TRACE_EVENT(intel_pipe_disable,
@@ -81,11 +101,8 @@ TRACE_EVENT(intel_pipe_disable,
 			   __entry->pipe_name = pipe_name(crtc->pipe);
 			   ),
 
-	    TP_printk("dev %s, pipe %c disable, pipe A: frame=%u, scanline=%u, pipe B: frame=%u, scanline=%u, pipe C: frame=%u, scanline=%u",
-		      __get_str(dev), __entry->pipe_name,
-		      __entry->frame[_TRACE_PIPE_A], __entry->scanline[_TRACE_PIPE_A],
-		      __entry->frame[_TRACE_PIPE_B], __entry->scanline[_TRACE_PIPE_B],
-		      __entry->frame[_TRACE_PIPE_C], __entry->scanline[_TRACE_PIPE_C])
+	    TP_printk("dev %s, pipe %c disable, " _PIPES_FRAME_AND_SCANLINE_FMT,
+		      __get_str(dev), __entry->pipe_name, _PIPES_FRAME_AND_SCANLINE_VALUES)
 );
 
 TRACE_EVENT(intel_crtc_flip_done,
@@ -211,11 +228,9 @@ TRACE_EVENT(intel_memory_cxsr,
 			   __entry->new = new;
 			   ),
 
-	    TP_printk("dev %s, cxsr %s->%s, pipe A: frame=%u, scanline=%u, pipe B: frame=%u, scanline=%u, pipe C: frame=%u, scanline=%u",
+	    TP_printk("dev %s, cxsr %s->%s, " _PIPES_FRAME_AND_SCANLINE_FMT,
 		      __get_str(dev), str_on_off(__entry->old), str_on_off(__entry->new),
-		      __entry->frame[_TRACE_PIPE_A], __entry->scanline[_TRACE_PIPE_A],
-		      __entry->frame[_TRACE_PIPE_B], __entry->scanline[_TRACE_PIPE_B],
-		      __entry->frame[_TRACE_PIPE_C], __entry->scanline[_TRACE_PIPE_C])
+		      _PIPES_FRAME_AND_SCANLINE_VALUES)
 );
 
 TRACE_EVENT(g4x_wm,
-- 
2.46.0