Commit de968532 authored by Ville Syrjälä's avatar Ville Syrjälä
Browse files

drm/i915/dsb: Introduce intel_dsb_wait_usec() 



Add a function to emit the DSB "wait usecs" instruction.
This is just a usleep() for the DSB.

As a lower bound it seems pretty accurate, but the upper bound
seemed oddly relaxed (ie. sometimes I've seen waits that are
quite a bit longer than specified, not sure why).

Reviewed-by: default avatarAnimesh Manna <animesh.manna@intel.com>
Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240930170415.23841-7-ville.syrjala@linux.intel.com
parent 63b41d20

drivers/gpu/drm/i915/display/intel_dsb.c

+6 −0
Original line number Diff line number Diff line
@@ -393,6 +393,12 @@ void intel_dsb_interrupt(struct intel_dsb *dsb) 
		       DSB_OPCODE_INTERRUPT << DSB_OPCODE_SHIFT);

}



void intel_dsb_wait_usec(struct intel_dsb *dsb, int count)

{

	intel_dsb_emit(dsb, count,

		       DSB_OPCODE_WAIT_USEC << DSB_OPCODE_SHIFT);

}



static void intel_dsb_emit_wait_dsl(struct intel_dsb *dsb,

				    u32 opcode, int lower, int upper)

{

drivers/gpu/drm/i915/display/intel_dsb.h

+1 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ void intel_dsb_noop(struct intel_dsb *dsb, int count); 
void intel_dsb_nonpost_start(struct intel_dsb *dsb);

void intel_dsb_nonpost_end(struct intel_dsb *dsb);

void intel_dsb_interrupt(struct intel_dsb *dsb);

void intel_dsb_wait_usec(struct intel_dsb *dsb, int count);

void intel_dsb_wait_scanline_in(struct intel_atomic_state *state,

				struct intel_dsb *dsb,

				int lower, int upper);