drm/i915: Add code comment on assumption of pipe==transcoder (8f78df90) · Commits · 戴 / test

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:

Imre 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

drivers/gpu/drm/i915/intel_display.h

+19 −3

Original line number	Diff line number	Diff line
		@@ -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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