Commit 8f78df90 authored by Imre Deak's avatar Imre Deak
Browse files

drm/i915: Add code comment on assumption of pipe==transcoder



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)
v3: (Lucas)
- s/->/ -> / so it looks less like pointer dereferencing.
- Use pipe enums as initializers in the transcoder enum definition.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: Mika Kahola <mika.kahola@intel.com>
Signed-off-by: default avatarImre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> (v2)
Link: https://patchwork.freedesktop.org/patch/msgid/20181120092325.21249-3-imre.deak@intel.com
parent c0871805
......@@ -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 {
TRANSCODER_A = 0,
TRANSCODER_B,
TRANSCODER_C,
/*
* 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 = PIPE_A,
TRANSCODER_B = PIPE_B,
TRANSCODER_C = PIPE_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,
......
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