drm/amd/display: add a option to force the clock at every mode change.

[Description]
This is for HW negative stress testing use.
force reset the dispclk and dppclk even the same clock already set in HW.

Signed-off-by: Charlene Liu <charlene.liu@amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c
index 9a873e2..3cff4f0 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c
+++ b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c
@@ -151,7 +151,14 @@ void dcn2_update_clocks(struct clk_mgr *clk_mgr_base,
        bool enter_display_off = false;
        bool dpp_clock_lowered = false;
        struct dmcu *dmcu = clk_mgr_base->ctx->dc->res_pool->dmcu;
+       bool force_reset = false;
 
+       if (clk_mgr_base->clks.dispclk_khz == 0 ||
+               dc->debug.force_clock_mode & 0x1) {
+               //this is from resume or boot up, if forced_clock cfg option used, we bypass program dispclk and DPPCLK, but need set them for S3.
+               force_reset = true;
+               //force_clock_mode 0x1:  force reset the clock even it is the same clock as long as it is in Passive level.
+       }
        display_count = clk_mgr_helper_get_active_display_cnt(dc, context);
        if (dc->res_pool->pp_smu)
                pp_smu = &dc->res_pool->pp_smu->nv_funcs;
@@ -223,7 +230,7 @@ void dcn2_update_clocks(struct clk_mgr *clk_mgr_base,
 
                update_dispclk = true;
        }
-       if (dc->config.forced_clocks == false) {
+       if (dc->config.forced_clocks == false || (force_reset && safe_to_lower)) {
                if (dpp_clock_lowered) {
                        // if clock is being lowered, increase DTO before lowering refclk
                        dcn20_update_clocks_update_dpp_dto(clk_mgr, context);

diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h
index a5b5afd..584fabf 100644 (file)
--- a/drivers/gpu/drm/amd/display/dc/dc.h
+++ b/drivers/gpu/drm/amd/display/dc/dc.h
@@ -385,6 +385,7 @@ struct dc_debug_options {
 #if defined(CONFIG_DRM_AMD_DC_DCN2_0)
        bool cm_in_bypass;
 #endif
+       int force_clock_mode;/*every mode change.*/
 };
 
 struct dc_debug_data {