[PATCH 23/24] drm/amd/display: avoid reset DTBCLK at clock init

[Tom Chung]

From: Charlene Liu <charlene....@amd.com>

[why & how]
this is to init to HW real DTBCLK.
and use real HW DTBCLK status to update internal logic state

Reviewed-by: Nicholas Kazlauskas <nicholas.kazlaus...@amd.com>
Reviewed-by: Martin Leung <martin.le...@amd.com>
Signed-off-by: Charlene Liu <charlene....@amd.com>
Signed-off-by: Ausef Yousof <ausef.you...@amd.com>
Signed-off-by: Tom Chung <chiahsuan.ch...@amd.com>
---
 .../display/dc/clk_mgr/dcn35/dcn35_clk_mgr.c   | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn35/dcn35_clk_mgr.c 
b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn35/dcn35_clk_mgr.c
index 2a74140d7ebf..1f974ea3b0c6 100644
--- a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn35/dcn35_clk_mgr.c
+++ b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn35/dcn35_clk_mgr.c
@@ -401,6 +401,7 @@ void dcn35_update_clocks(struct clk_mgr *clk_mgr_base,
                if (clk_mgr_base->clks.dtbclk_en && !new_clocks->dtbclk_en) {
                        if (clk_mgr->base.ctx->dc->config.allow_0_dtb_clk)
                                dcn35_smu_set_dtbclk(clk_mgr, false);
+
                        clk_mgr_base->clks.dtbclk_en = new_clocks->dtbclk_en;
                }
                /* check that we're not already in lower */
@@ -418,11 +419,17 @@ void dcn35_update_clocks(struct clk_mgr *clk_mgr_base,
                }
 
                if (!clk_mgr_base->clks.dtbclk_en && new_clocks->dtbclk_en) {
-                       dcn35_smu_set_dtbclk(clk_mgr, true);
-                       clk_mgr_base->clks.dtbclk_en = new_clocks->dtbclk_en;
+                       int actual_dtbclk = 0;
 
                        dcn35_update_clocks_update_dtb_dto(clk_mgr, context, 
new_clocks->ref_dtbclk_khz);
-                       clk_mgr_base->clks.ref_dtbclk_khz = 
new_clocks->ref_dtbclk_khz;
+                       dcn35_smu_set_dtbclk(clk_mgr, true);
+
+                       actual_dtbclk = REG_READ(CLK1_CLK4_CURRENT_CNT);
+
+                       if (actual_dtbclk) {
+                               clk_mgr_base->clks.ref_dtbclk_khz = 
new_clocks->ref_dtbclk_khz;
+                               clk_mgr_base->clks.dtbclk_en = 
new_clocks->dtbclk_en;
+                       }
                }
 
                /* check that we're not already in D0 */
@@ -584,12 +591,10 @@ static bool dcn35_is_spll_ssc_enabled(struct clk_mgr 
*clk_mgr_base)
 
 static void init_clk_states(struct clk_mgr *clk_mgr)
 {
-       struct clk_mgr_internal *clk_mgr_int = TO_CLK_MGR_INTERNAL(clk_mgr);
        uint32_t ref_dtbclk = clk_mgr->clks.ref_dtbclk_khz;
+
        memset(&(clk_mgr->clks), 0, sizeof(struct dc_clocks));
 
-       if (clk_mgr_int->smu_ver >= SMU_VER_THRESHOLD)
-               clk_mgr->clks.dtbclk_en = true; // request DTBCLK disable on 
first commit
        clk_mgr->clks.ref_dtbclk_khz = ref_dtbclk;      // restore ref_dtbclk
        clk_mgr->clks.p_state_change_support = true;
        clk_mgr->clks.prev_p_state_change_support = true;
@@ -600,6 +605,7 @@ static void init_clk_states(struct clk_mgr *clk_mgr)
 void dcn35_init_clocks(struct clk_mgr *clk_mgr)
 {
        struct clk_mgr_internal *clk_mgr_int = TO_CLK_MGR_INTERNAL(clk_mgr);
+
        init_clk_states(clk_mgr);
 
        // to adjust dp_dto reference clock if ssc is enable otherwise to apply 
dprefclk
-- 
2.34.1