[Intel-gfx] [PATCH 3/3] drm/i915: Add code comment on assumption of pipe==transcoder

[Imre Deak]

Add a comment to the pipe and transcoder enum definitions about our
assumption in the code that pipe==transcoder for PIPE_A-C /
TRANSCODER_A-C. This means we have to keep the values for these
pipe/transcoder enums fixed.

Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Cc: Lucas De Marchi <lucas.demarchi at intel.com>
Cc: Mika Kahola <mika.kahola at intel.com>
Signed-off-by: Imre Deak <imre.deak at intel.com>
---
 drivers/gpu/drm/i915/intel_display.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_display.h b/drivers/gpu/drm/i915/intel_display.h
index 43eb4ebbcc35..cbb5d79d6a4c 100644
--- a/drivers/gpu/drm/i915/intel_display.h
+++ b/drivers/gpu/drm/i915/intel_display.h
@@ -43,6 +43,10 @@ enum i915_gpio {
 	GPIOM,
 };
 
+/*
+ * Keep the PIPE_A-C values fixed, we assume that pipe==transcoder for
+ * these pipes.
+ */
 enum pipe {
 	INVALID_PIPE = -1,
 
@@ -56,6 +60,10 @@ enum pipe {
 
 #define pipe_name(p) ((p) + 'A')
 
+/*
+ * Keep the TRANSCODER_A-C values fixed, we assume that pipe==transcoder for
+ * these transcoders.
+ */
 enum transcoder {
 	TRANSCODER_A = 0,
 	TRANSCODER_B,
-- 
2.13.2