Add a comment to the pipe and transcoder enum definitions about our
assumption in the code about enum values for pipes and transcoders
with a 1:1 transcoder->pipe mapping.
v2:
- Clarify more what are the assumptions about the enum values. (Ville)
Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Cc: Lucas De Marchi <lucas.demarchi@xxxxxxxxx>
Cc: Mika Kahola <mika.kahola@xxxxxxxxx>
Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
Reviewed-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/intel_display.h | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/drivers/gpu/drm/i915/intel_display.h b/drivers/gpu/drm/i915/intel_display.h
index 43eb4ebbcc35..846f63d056fb 100644
--- a/drivers/gpu/drm/i915/intel_display.h
+++ b/drivers/gpu/drm/i915/intel_display.h
@@ -43,6 +43,11 @@ enum i915_gpio {
GPIOM,
};
+/*
+ * Keep the pipe enum values fixed: the code assumes that PIPE_A=0, the
+ * rest have consecutive values and match the enum values of transcoders
+ * with a 1:1 transcoder->pipe mapping.
+ */
enum pipe {
INVALID_PIPE = -1,
@@ -57,9 +62,20 @@ enum pipe {
#define pipe_name(p) ((p) + 'A')
enum transcoder {
+ /*
+ * The following transcoders have a 1:1 transcoder->pipe mapping, keep
+ * their values fixed: the code assumes that TRANSCODER_A=0, the rest
+ * have consecutive values and match the enum values of the pipes they
+ * map to.
+ */
TRANSCODER_A = 0,
TRANSCODER_B,
TRANSCODER_C,
+
+ /*
+ * The following transcoders can map to any pipe, their enum value
+ * doesn't need to stay fixed.
+ */
TRANSCODER_EDP,
TRANSCODER_DSI_0,
TRANSCODER_DSI_1,
--
2.13.2
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
