Commit 76174867 authored by Ville Syrjälä's avatar Ville Syrjälä
Browse files

drm/i915/dmc: Reload pipe DMC state on TGL when enabling pipe A 



On TGL/derivatives the entire pipe DMC state (program + MMIO) is
lost when PG1 is disabled, and the main DMC does not restore
any of it. Reload the state when enabling a pipe.

The other option would be to not load the pipe DMC at all since
it's only needed for "fast LACE" (which we don't use) on these
platforms. But let's keep it around just in case we ever decide
that "fast LACE" is something we want.

Reviewed-by: default avatarUma Shankar <uma.shankar@intel.com>
Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250617170759.19552-6-ville.syrjala@linux.intel.com
parent c541ad77

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

+9 −0
Original line number Diff line number Diff line
@@ -600,6 +600,12 @@ static void dmc_load_program(struct intel_display *display, 
	}

}



static bool need_pipedmc_load_program(struct intel_display *display)

{

	/* On TGL/derivatives pipe DMC state is lost when PG1 is disabled */

	return DISPLAY_VER(display) == 12;

}



void intel_dmc_enable_pipe(struct intel_display *display, enum pipe pipe)

{

	enum intel_dmc_id dmc_id = PIPE_TO_DMC_ID(pipe);
@@ -607,6 +613,9 @@ void intel_dmc_enable_pipe(struct intel_display *display, enum pipe pipe) 
	if (!is_valid_dmc_id(dmc_id) || !has_dmc_id_fw(display, dmc_id))

		return;



	if (need_pipedmc_load_program(display))

		dmc_load_program(display, dmc_id);



	if (DISPLAY_VER(display) >= 20) {

		intel_de_write(display, PIPEDMC_INTERRUPT(pipe), pipedmc_interrupt_mask(display));

		intel_de_write(display, PIPEDMC_INTERRUPT_MASK(pipe), ~pipedmc_interrupt_mask(display));