drm/amd/display: Power-gate all DSCs at driver init time

[why]
DSC should be powered-on only on as-needed basis, i.e. if the mode
requires it

[how]
Loop over all the DSCs at driver init time and power-gate each
Signed-off-by: Nikola Cornij <nikola.cornij@amd.com>
Reviewed-by: Nevenko Stupar <Nevenko.Stupar@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c

@@ -624,6 +624,10 @@ static void dcn20_init_hw(struct dc *dc)
 		}
 	}
 
+	/* Power gate DSCs */
+	for (i = 0; i < res_pool->res_cap->num_dsc; i++)
+		dcn20_dsc_pg_control(hws, res_pool->dscs[i]->inst, false);
+
 	/* Blank pixel data with OPP DPG */
 	for (i = 0; i < dc->res_pool->timing_generator_count; i++) {
 		struct timing_generator *tg = dc->res_pool->timing_generators[i];