Skip to contentSkip to conversation

FAILED: patch "[PATCH] drm/amd/display: Prevent Gating DTBCLK before It Is Properly" failed to apply to 6.12-stable tree

PATCH New [email protected] 2 participants 5 messages Nov 24, 2025 – Nov 25, 2025

Subsystems (4)
Stable branch DRM drivers Radeon and amdgpu DRM drivers AMD display core
lore
Share & tools
lore

[email protected]

author maintainer
#0 lore raw

The patch below does not apply to the 6.12-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y
git checkout FETCH_HEAD
git cherry-pick -x cfa0904a35fd0231f4d05da0190f0a22ed881cce
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2025112425-aspirin-conduit-e44b@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From cfa0904a35fd0231f4d05da0190f0a22ed881cce Mon Sep 17 00:00:00 2001
From: Fangzhi Zuo <[email protected]>
Date: Thu, 18 Sep 2025 16:25:45 -0400
Subject: [PATCH] drm/amd/display: Prevent Gating DTBCLK before It Is Properly
Latched

[why]
1. With allow_0_dtb_clk enabled, the time required to latch DTBCLK to 600 MHz depends on the SMU. If DTBCLK is not latched to 600 MHz before set_mode completes, gating DTBCLK causes the DP2 sink to lose its clock source.

2. The existing DTBCLK gating sequence ungates DTBCLK based on both pix_clk and ref_dtbclk, but gates DTBCLK when either pix_clk or ref_dtbclk is zero.
pix_clk can be zero outside the set_mode sequence before DTBCLK is properly latched, which can lead to DTBCLK being gated by mistake.

[how]
Consider both pixel_clk and ref_dtbclk when determining when it is safe to gate DTBCLK; this is more accurate.

Closes https://gitlab.freedesktop.org/drm/amd/-/issues/4701
Fixes 5949e7c4890c ("drm/amd/display: Enable Dynamic DTBCLK Switch")
Reviewed-by Charlene Liu <[email protected]>
Reviewed-by Aurabindo Pillai <[email protected]>
Signed-off-by Fangzhi Zuo <[email protected]>
Signed-off-by Roman Li <[email protected]>
Tested-by Dan Wheeler <[email protected]>
Signed-off-by Alex Deucher <[email protected]>
(cherry picked from commit d04eb0c402780ca037b62a6aecf23b863545ebca)
Cc [email protected]
drivers/gpu/drm/amd/display/dc/clk_mgr/dcn35/dcn35_clk_mgr.c +3 -1
index b11383fba35f..1eb04772f5da 100644
@@ -394,6 +394,8 @@ void dcn35_update_clocks(struct clk_mgr *clk_mgr_base,
 	display_count = dcn35_get_active_display_cnt_wa(dc, context, &all_active_disps);
 	if (new_clocks->dtbclk_en && !new_clocks->ref_dtbclk_khz)
 		new_clocks->ref_dtbclk_khz = 600000;
+	else if (!new_clocks->dtbclk_en && new_clocks->ref_dtbclk_khz > 590000)
+		new_clocks->ref_dtbclk_khz = 0;
 
 	/*
 	 * if it is safe to lower, but we are already in the lower state, we don't have to do anything

@@ -435,7 +437,7 @@ void dcn35_update_clocks(struct clk_mgr *clk_mgr_base,
 
 			actual_dtbclk = REG_READ(CLK1_CLK4_CURRENT_CNT);
 
-			if (actual_dtbclk) {
+			if (actual_dtbclk > 590000) {
 				clk_mgr_base->clks.ref_dtbclk_khz = new_clocks->ref_dtbclk_khz;
 				clk_mgr_base->clks.dtbclk_en = new_clocks->dtbclk_en;
 			}
drivers/gpu/drm/amd/display/dc/dccg/dcn35/dcn35_dccg.c +1 -1
index de6d62401362..c899c09ea31b 100644
@@ -1411,7 +1411,7 @@ static void dccg35_set_dtbclk_dto(
 				__func__, params->otg_inst, params->pixclk_khz,
 				params->ref_dtbclk_khz, req_dtbclk_khz, phase, modulo);
 
-	} else {
+	} else if (!params->ref_dtbclk_khz && !req_dtbclk_khz) {
 		switch (params->otg_inst) {
 		case 0:
 			REG_UPDATE(DCCG_GATE_DISABLE_CNTL5, DTBCLK_P0_GATE_DISABLE, 0);
maintainer
#1 lore raw

PATCH 1/4 drm/amd/display: avoid reset DTBCLK at clock init

From: Charlene Liu <[email protected]>

[ Upstream commit 0ae47e971b9add8f7b8f8d55ac5f407f6f346758 ]

[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 <[email protected]>
Reviewed-by Martin Leung <[email protected]>
Signed-off-by Charlene Liu <[email protected]>
Signed-off-by Ausef Yousof <[email protected]>
Signed-off-by Tom Chung <[email protected]>
Tested-by Daniel Wheeler <[email protected]>
Signed-off-by Alex Deucher <[email protected]>

Stable-dep-of: cfa0904a35fd ("drm/amd/display: Prevent Gating DTBCLK before It Is Properly Latched")

Signed-off-by Sasha Levin <[email protected]>
---
 .../display/dc/clk_mgr/dcn35/dcn35_clk_mgr.c   | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)
drivers/gpu/drm/amd/display/dc/clk_mgr/dcn35/dcn35_clk_mgr.c +12 -6
index a4ac601a30c35..3114b3fae9eff 100644
@@ -393,6 +393,7 @@ 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 */

@@ -410,11 +411,17 @@ 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 */

@@ -581,12 +588,10 @@ 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;

@@ -597,6 +602,7 @@ 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
Signature · 1 line
2.51.0
maintainer
#2 lore raw

PATCH 2/4 drm/amd/display: disable DPP RCG before DPP CLK enable

From: Charlene Liu <[email protected]>

[ Upstream commit 1bcd679209420305a86833bc357d50021909edaf ]

[why]
DPP CLK enable needs to disable DPPCLK RCG first.
The DPPCLK_en in dccg should always be enabled when the corresponding pipe is enabled.

Reviewed-by Hansen Dsouza <[email protected]>
Signed-off-by Charlene Liu <[email protected]>
Signed-off-by Ray Wu <[email protected]>
Tested-by Daniel Wheeler <[email protected]>
Signed-off-by Alex Deucher <[email protected]>

Stable-dep-of: cfa0904a35fd ("drm/amd/display: Prevent Gating DTBCLK before It Is Properly Latched")

Signed-off-by Sasha Levin <[email protected]>
---
 .../amd/display/dc/dccg/dcn35/dcn35_dccg.c    | 38 ++++++++++++-------
 .../amd/display/dc/hwss/dcn35/dcn35_hwseq.c   | 21 ++++++----
 2 files changed, 38 insertions(+), 21 deletions(-)
drivers/gpu/drm/amd/display/dc/dccg/dcn35/dcn35_dccg.c +24 -14
index b363f5360818d..ad910065f463f 100644
@@ -391,6 +391,7 @@ static void dccg35_set_dppclk_rcg(struct dccg *dccg,
 
 	struct dcn_dccg *dccg_dcn = TO_DCN_DCCG(dccg);
 
+
 	if (!dccg->ctx->dc->debug.root_clock_optimization.bits.dpp && enable)
 		return;
 

@@ -411,6 +412,8 @@ static void dccg35_set_dppclk_rcg(struct dccg *dccg,
 	BREAK_TO_DEBUGGER();
 		break;
 	}
+	//DC_LOG_DEBUG("%s: inst(%d) DPPCLK rcg_disable: %d\n", __func__, inst, enable ? 0 : 1);
+
 }
 
 static void dccg35_set_dpstreamclk_rcg(

@@ -1112,30 +1115,24 @@ static void dcn35_set_dppclk_enable(struct dccg *dccg,
 {
 	struct dcn_dccg *dccg_dcn = TO_DCN_DCCG(dccg);
 
+
 	switch (dpp_inst) {
 	case 0:
 		REG_UPDATE(DPPCLK_CTRL, DPPCLK0_EN, enable);
-		if (dccg->ctx->dc->debug.root_clock_optimization.bits.dpp)
-			REG_UPDATE(DCCG_GATE_DISABLE_CNTL6, DPPCLK0_ROOT_GATE_DISABLE, enable);
 		break;
 	case 1:
 		REG_UPDATE(DPPCLK_CTRL, DPPCLK1_EN, enable);
-		if (dccg->ctx->dc->debug.root_clock_optimization.bits.dpp)
-			REG_UPDATE(DCCG_GATE_DISABLE_CNTL6, DPPCLK1_ROOT_GATE_DISABLE, enable);
 		break;
 	case 2:
 		REG_UPDATE(DPPCLK_CTRL, DPPCLK2_EN, enable);
-		if (dccg->ctx->dc->debug.root_clock_optimization.bits.dpp)
-			REG_UPDATE(DCCG_GATE_DISABLE_CNTL6, DPPCLK2_ROOT_GATE_DISABLE, enable);
 		break;
 	case 3:
 		REG_UPDATE(DPPCLK_CTRL, DPPCLK3_EN, enable);
-		if (dccg->ctx->dc->debug.root_clock_optimization.bits.dpp)
-			REG_UPDATE(DCCG_GATE_DISABLE_CNTL6, DPPCLK3_ROOT_GATE_DISABLE, enable);
 		break;
 	default:
 		break;
 	}
+	//DC_LOG_DEBUG("%s: dpp_inst(%d) DPPCLK_EN = %d\n", __func__, dpp_inst, enable);
 
 }
 

@@ -1163,14 +1160,18 @@ static void dccg35_update_dpp_dto(struct dccg *dccg, int dpp_inst,
 			ASSERT(false);
 			phase = 0xff;
 		}
+		dccg35_set_dppclk_rcg(dccg, dpp_inst, false);
 
 		REG_SET_2(DPPCLK_DTO_PARAM[dpp_inst], 0,
 				DPPCLK0_DTO_PHASE, phase,
 				DPPCLK0_DTO_MODULO, modulo);
 
 		dcn35_set_dppclk_enable(dccg, dpp_inst, true);
-	} else
+	} else {
 		dcn35_set_dppclk_enable(dccg, dpp_inst, false);
+		/*we have this in hwss: disable_plane*/
+		//dccg35_set_dppclk_rcg(dccg, dpp_inst, true);
+	}
 	dccg->pipe_dppclk_khz[dpp_inst] = req_dppclk;
 }
 

@@ -1182,6 +1183,7 @@ static void dccg35_set_dppclk_root_clock_gating(struct dccg *dccg,
 	if (!dccg->ctx->dc->debug.root_clock_optimization.bits.dpp)
 		return;
 
+
 	switch (dpp_inst) {
 	case 0:
 		REG_UPDATE(DCCG_GATE_DISABLE_CNTL6, DPPCLK0_ROOT_GATE_DISABLE, enable);

@@ -1198,6 +1200,8 @@ static void dccg35_set_dppclk_root_clock_gating(struct dccg *dccg,
 	default:
 		break;
 	}
+	//DC_LOG_DEBUG("%s: dpp_inst(%d) rcg: %d\n", __func__, dpp_inst, enable);
+
 }
 
 static void dccg35_get_pixel_rate_div(

@@ -1521,28 +1525,30 @@ static void dccg35_set_physymclk_root_clock_gating(
 	switch (phy_inst) {
 	case 0:
 		REG_UPDATE(DCCG_GATE_DISABLE_CNTL2,
-				PHYASYMCLK_ROOT_GATE_DISABLE, enable ? 1 : 0);
+				PHYASYMCLK_ROOT_GATE_DISABLE, enable ? 0 : 1);
 		break;
 	case 1:
 		REG_UPDATE(DCCG_GATE_DISABLE_CNTL2,
-				PHYBSYMCLK_ROOT_GATE_DISABLE, enable ? 1 : 0);
+				PHYBSYMCLK_ROOT_GATE_DISABLE, enable ? 0 : 1);
 		break;
 	case 2:
 		REG_UPDATE(DCCG_GATE_DISABLE_CNTL2,
-				PHYCSYMCLK_ROOT_GATE_DISABLE, enable ? 1 : 0);
+				PHYCSYMCLK_ROOT_GATE_DISABLE, enable ? 0 : 1);
 		break;
 	case 3:
 		REG_UPDATE(DCCG_GATE_DISABLE_CNTL2,
-				PHYDSYMCLK_ROOT_GATE_DISABLE, enable ? 1 : 0);
+				PHYDSYMCLK_ROOT_GATE_DISABLE, enable ? 0 : 1);
 		break;
 	case 4:
 		REG_UPDATE(DCCG_GATE_DISABLE_CNTL2,
-				PHYESYMCLK_ROOT_GATE_DISABLE, enable ? 1 : 0);
+				PHYESYMCLK_ROOT_GATE_DISABLE, enable ? 0 : 1);
 		break;
 	default:
 		BREAK_TO_DEBUGGER();
 		return;
 	}
+	//DC_LOG_DEBUG("%s: dpp_inst(%d) PHYESYMCLK_ROOT_GATE_DISABLE:\n", __func__, phy_inst, enable ? 0 : 1);
+
 }
 
 static void dccg35_set_physymclk(

@@ -1643,6 +1649,8 @@ static void dccg35_dpp_root_clock_control(
 		return;
 
 	if (clock_on) {
+		dccg35_set_dppclk_rcg(dccg, dpp_inst, false);
+
 		/* turn off the DTO and leave phase/modulo at max */
 		dcn35_set_dppclk_enable(dccg, dpp_inst, 1);
 		REG_SET_2(DPPCLK_DTO_PARAM[dpp_inst], 0,

@@ -1654,6 +1662,8 @@ static void dccg35_dpp_root_clock_control(
 		REG_SET_2(DPPCLK_DTO_PARAM[dpp_inst], 0,
 			  DPPCLK0_DTO_PHASE, 0,
 			  DPPCLK0_DTO_MODULO, 1);
+		/*we have this in hwss: disable_plane*/
+		//dccg35_set_dppclk_rcg(dccg, dpp_inst, true);
 	}
 
 	dccg->dpp_clock_gated[dpp_inst] = !clock_on;
drivers/gpu/drm/amd/display/dc/hwss/dcn35/dcn35_hwseq.c +14 -7
index 21aff7fa6375d..c739e5b2c5595 100644
@@ -241,11 +241,6 @@ void dcn35_init_hw(struct dc *dc)
 			dc->res_pool->hubbub->funcs->allow_self_refresh_control(dc->res_pool->hubbub,
 					!dc->res_pool->hubbub->ctx->dc->debug.disable_stutter);
 	}
-	if (res_pool->dccg->funcs->dccg_root_gate_disable_control) {
-		for (i = 0; i < res_pool->pipe_count; i++)
-			res_pool->dccg->funcs->dccg_root_gate_disable_control(res_pool->dccg, i, 0);
-	}
-
 	for (i = 0; i < res_pool->audio_count; i++) {
 		struct audio *audio = res_pool->audios[i];
 

@@ -885,12 +880,18 @@ void dcn35_init_pipes(struct dc *dc, struct dc_state *context)
 void dcn35_enable_plane(struct dc *dc, struct pipe_ctx *pipe_ctx,
 			       struct dc_state *context)
 {
+	struct dpp *dpp = pipe_ctx->plane_res.dpp;
+	struct dccg *dccg = dc->res_pool->dccg;
+
+
 	/* enable DCFCLK current DCHUB */
 	pipe_ctx->plane_res.hubp->funcs->hubp_clk_cntl(pipe_ctx->plane_res.hubp, true);
 
 	/* initialize HUBP on power up */
 	pipe_ctx->plane_res.hubp->funcs->hubp_init(pipe_ctx->plane_res.hubp);
-
+	/*make sure DPPCLK is on*/
+	dccg->funcs->dccg_root_gate_disable_control(dccg, dpp->inst, true);
+	dpp->funcs->dpp_dppclk_control(dpp, false, true);
 	/* make sure OPP_PIPE_CLOCK_EN = 1 */
 	pipe_ctx->stream_res.opp->funcs->opp_pipe_clock_control(
 			pipe_ctx->stream_res.opp,

@@ -907,6 +908,7 @@ void dcn35_enable_plane(struct dc *dc, struct pipe_ctx *pipe_ctx,
 		// Program system aperture settings
 		pipe_ctx->plane_res.hubp->funcs->hubp_set_vm_system_aperture_settings(pipe_ctx->plane_res.hubp, &apt);
 	}
+	//DC_LOG_DEBUG("%s: dpp_inst(%d) =\n", __func__, dpp->inst);
 
 	if (!pipe_ctx->top_pipe
 		&& pipe_ctx->plane_state

@@ -922,6 +924,8 @@ void dcn35_plane_atomic_disable(struct dc *dc, struct pipe_ctx *pipe_ctx)
 {
 	struct hubp *hubp = pipe_ctx->plane_res.hubp;
 	struct dpp *dpp = pipe_ctx->plane_res.dpp;
+	struct dccg *dccg = dc->res_pool->dccg;
+
 
 	dc->hwss.wait_for_mpcc_disconnect(dc, dc->res_pool, pipe_ctx);
 

@@ -939,7 +943,8 @@ void dcn35_plane_atomic_disable(struct dc *dc, struct pipe_ctx *pipe_ctx)
 	hubp->funcs->hubp_clk_cntl(hubp, false);
 
 	dpp->funcs->dpp_dppclk_control(dpp, false, false);
-/*to do, need to support both case*/
+	dccg->funcs->dccg_root_gate_disable_control(dccg, dpp->inst, false);
+
 	hubp->power_gated = true;
 
 	hubp->funcs->hubp_reset(hubp);

@@ -951,6 +956,8 @@ void dcn35_plane_atomic_disable(struct dc *dc, struct pipe_ctx *pipe_ctx)
 	pipe_ctx->top_pipe = NULL;
 	pipe_ctx->bottom_pipe = NULL;
 	pipe_ctx->plane_state = NULL;
+	//DC_LOG_DEBUG("%s: dpp_inst(%d)=\n", __func__, dpp->inst);
+
 }
 
 void dcn35_disable_plane(struct dc *dc, struct dc_state *state, struct pipe_ctx *pipe_ctx)
Signature · 1 line
2.51.0
maintainer
#3 lore raw

PATCH 3/4 drm/amd/display: Insert dccg log for easy debug

In reply to Sasha Levin

From: Charlene Liu <[email protected]>

[ Upstream commit 35bcc9168f3ce6416cbf3f776758be0937f84cb3 ]

[why]
Log for sequence tracking

Reviewed-by Ovidiu (Ovi) Bunea <[email protected]>
Reviewed-by Yihan Zhu <[email protected]>
Signed-off-by Charlene Liu <[email protected]>
Signed-off-by Ivan Lipski <[email protected]>
Tested-by Dan Wheeler <[email protected]>
Signed-off-by Alex Deucher <[email protected]>

Stable-dep-of: cfa0904a35fd ("drm/amd/display: Prevent Gating DTBCLK before It Is Properly Latched")

Signed-off-by Sasha Levin <[email protected]>
---
 .../amd/display/dc/dccg/dcn35/dcn35_dccg.c    | 24 ++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)
drivers/gpu/drm/amd/display/dc/dccg/dcn35/dcn35_dccg.c +21 -3
index ad910065f463f..a841eaafbaaa8 100644
@@ -39,6 +39,7 @@
 
 #define CTX \
 	dccg_dcn->base.ctx
+#include "logger_types.h"
 #define DC_LOGGER \
 	dccg->ctx->logger
 

@@ -1132,7 +1133,7 @@ static void dcn35_set_dppclk_enable(struct dccg *dccg,
 	default:
 		break;
 	}
-	//DC_LOG_DEBUG("%s: dpp_inst(%d) DPPCLK_EN = %d\n", __func__, dpp_inst, enable);
+	DC_LOG_DEBUG("%s: dpp_inst(%d) DPPCLK_EN = %d\n", __func__, dpp_inst, enable);
 
 }
 

@@ -1400,6 +1401,10 @@ static void dccg35_set_dtbclk_dto(
 		 * PIPEx_DTO_SRC_SEL should not be programmed during DTBCLK update since OTG may still be on, and the
 		 * programming is handled in program_pix_clk() regardless, so it can be removed from here.
 		 */
+		DC_LOG_DEBUG("%s: OTG%d DTBCLK DTO enabled: pixclk_khz=%d, ref_dtbclk_khz=%d, req_dtbclk_khz=%d, phase=%d, modulo=%d\n",
+				__func__, params->otg_inst, params->pixclk_khz,
+				params->ref_dtbclk_khz, req_dtbclk_khz, phase, modulo);
+
 	} else {
 		switch (params->otg_inst) {
 		case 0:

@@ -1425,6 +1430,8 @@ static void dccg35_set_dtbclk_dto(
 
 		REG_WRITE(DTBCLK_DTO_MODULO[params->otg_inst], 0);
 		REG_WRITE(DTBCLK_DTO_PHASE[params->otg_inst], 0);
+
+		DC_LOG_DEBUG("%s: OTG%d DTBCLK DTO disabled\n", __func__, params->otg_inst);
 	}
 }
 

@@ -1469,6 +1476,8 @@ static void dccg35_set_dpstreamclk(
 		BREAK_TO_DEBUGGER();
 		return;
 	}
+	DC_LOG_DEBUG("%s: dp_hpo_inst(%d) DPSTREAMCLK_EN = %d, DPSTREAMCLK_SRC_SEL = %d\n",
+			__func__, dp_hpo_inst, (src == REFCLK) ? 0 : 1, otg_inst);
 }
 
 

@@ -1508,6 +1517,8 @@ static void dccg35_set_dpstreamclk_root_clock_gating(
 		BREAK_TO_DEBUGGER();
 		return;
 	}
+	DC_LOG_DEBUG("%s: dp_hpo_inst(%d) DPSTREAMCLK_ROOT_GATE_DISABLE = %d\n",
+			__func__, dp_hpo_inst, enable ? 1 : 0);
 }
 
 

@@ -1547,7 +1558,7 @@ static void dccg35_set_physymclk_root_clock_gating(
 		BREAK_TO_DEBUGGER();
 		return;
 	}
-	//DC_LOG_DEBUG("%s: dpp_inst(%d) PHYESYMCLK_ROOT_GATE_DISABLE:\n", __func__, phy_inst, enable ? 0 : 1);
+	DC_LOG_DEBUG("%s: dpp_inst(%d) PHYESYMCLK_ROOT_GATE_DISABLE: %d\n", __func__, phy_inst, enable ? 0 : 1);
 
 }
 

@@ -1620,6 +1631,8 @@ static void dccg35_set_physymclk(
 		BREAK_TO_DEBUGGER();
 		return;
 	}
+	DC_LOG_DEBUG("%s: phy_inst(%d) PHYxSYMCLK_EN = %d, PHYxSYMCLK_SRC_SEL = %d\n",
+			__func__, phy_inst, force_enable ? 1 : 0, clk_src);
 }
 
 static void dccg35_set_valid_pixel_rate(

@@ -1667,6 +1680,7 @@ static void dccg35_dpp_root_clock_control(
 	}
 
 	dccg->dpp_clock_gated[dpp_inst] = !clock_on;
+	DC_LOG_DEBUG("%s: dpp_inst(%d) clock_on = %d\n", __func__, dpp_inst, clock_on);
 }
 
 static void dccg35_disable_symclk32_se(

@@ -1725,6 +1739,7 @@ static void dccg35_disable_symclk32_se(
 		BREAK_TO_DEBUGGER();
 		return;
 	}
+
 }
 
 static void dccg35_init_cb(struct dccg *dccg)

@@ -1732,7 +1747,6 @@ static void dccg35_init_cb(struct dccg *dccg)
 	(void)dccg;
 	/* Any RCG should be done when driver enter low power mode*/
 }
-
 void dccg35_init(struct dccg *dccg)
 {
 	int otg_inst;

@@ -1747,6 +1761,8 @@ void dccg35_init(struct dccg *dccg)
 		for (otg_inst = 0; otg_inst < 2; otg_inst++) {
 			dccg31_disable_symclk32_le(dccg, otg_inst);
 			dccg31_set_symclk32_le_root_clock_gating(dccg, otg_inst, false);
+			DC_LOG_DEBUG("%s: OTG%d SYMCLK32_LE disabled and root clock gating disabled\n",
+					__func__, otg_inst);
 		}
 
 //	if (dccg->ctx->dc->debug.root_clock_optimization.bits.symclk32_se)

@@ -1759,6 +1775,8 @@ void dccg35_init(struct dccg *dccg)
 			dccg35_set_dpstreamclk(dccg, REFCLK, otg_inst,
 						otg_inst);
 			dccg35_set_dpstreamclk_root_clock_gating(dccg, otg_inst, false);
+			DC_LOG_DEBUG("%s: OTG%d DPSTREAMCLK disabled and root clock gating disabled\n",
+					__func__, otg_inst);
 		}
 
 /*
Signature · 1 line
2.51.0
maintainer
#4 lore raw

PATCH 4/4 drm/amd/display: Prevent Gating DTBCLK before It Is Properly Latched

In reply to Sasha Levin

From: Fangzhi Zuo <[email protected]>

[ Upstream commit cfa0904a35fd0231f4d05da0190f0a22ed881cce ]

[why]
1. With allow_0_dtb_clk enabled, the time required to latch DTBCLK to 600 MHz depends on the SMU. If DTBCLK is not latched to 600 MHz before set_mode completes, gating DTBCLK causes the DP2 sink to lose its clock source.

2. The existing DTBCLK gating sequence ungates DTBCLK based on both pix_clk and ref_dtbclk, but gates DTBCLK when either pix_clk or ref_dtbclk is zero.
pix_clk can be zero outside the set_mode sequence before DTBCLK is properly latched, which can lead to DTBCLK being gated by mistake.

[how]
Consider both pixel_clk and ref_dtbclk when determining when it is safe to gate DTBCLK; this is more accurate.

Closes https://gitlab.freedesktop.org/drm/amd/-/issues/4701
Fixes 5949e7c4890c ("drm/amd/display: Enable Dynamic DTBCLK Switch")
Reviewed-by Charlene Liu <[email protected]>
Reviewed-by Aurabindo Pillai <[email protected]>
Signed-off-by Fangzhi Zuo <[email protected]>
Signed-off-by Roman Li <[email protected]>
Tested-by Dan Wheeler <[email protected]>
Signed-off-by Alex Deucher <[email protected]>
(cherry picked from commit d04eb0c402780ca037b62a6aecf23b863545ebca)
Cc [email protected]
Signed-off-by Sasha Levin <[email protected]>
---
 drivers/gpu/drm/amd/display/dc/clk_mgr/dcn35/dcn35_clk_mgr.c | 4 +++-
 drivers/gpu/drm/amd/display/dc/dccg/dcn35/dcn35_dccg.c       | 2 +-
 2 files changed, 4 insertions(+), 2 deletions(-)
drivers/gpu/drm/amd/display/dc/clk_mgr/dcn35/dcn35_clk_mgr.c +3 -1
index 3114b3fae9eff..6e9d6090b10ff 100644
@@ -377,6 +377,8 @@ void dcn35_update_clocks(struct clk_mgr *clk_mgr_base,
 	display_count = dcn35_get_active_display_cnt_wa(dc, context, &all_active_disps);
 	if (new_clocks->dtbclk_en && !new_clocks->ref_dtbclk_khz)
 		new_clocks->ref_dtbclk_khz = 600000;
+	else if (!new_clocks->dtbclk_en && new_clocks->ref_dtbclk_khz > 590000)
+		new_clocks->ref_dtbclk_khz = 0;
 
 	/*
 	 * if it is safe to lower, but we are already in the lower state, we don't have to do anything

@@ -418,7 +420,7 @@ void dcn35_update_clocks(struct clk_mgr *clk_mgr_base,
 
 			actual_dtbclk = REG_READ(CLK1_CLK4_CURRENT_CNT);
 
-			if (actual_dtbclk) {
+			if (actual_dtbclk > 590000) {
 				clk_mgr_base->clks.ref_dtbclk_khz = new_clocks->ref_dtbclk_khz;
 				clk_mgr_base->clks.dtbclk_en = new_clocks->dtbclk_en;
 			}
drivers/gpu/drm/amd/display/dc/dccg/dcn35/dcn35_dccg.c +1 -1
index a841eaafbaaa8..57202ef3fd985 100644
@@ -1405,7 +1405,7 @@ static void dccg35_set_dtbclk_dto(
 				__func__, params->otg_inst, params->pixclk_khz,
 				params->ref_dtbclk_khz, req_dtbclk_khz, phase, modulo);
 
-	} else {
+	} else if (!params->ref_dtbclk_khz && !req_dtbclk_khz) {
 		switch (params->otg_inst) {
 		case 0:
 			REG_UPDATE(DCCG_GATE_DISABLE_CNTL5, DTBCLK_P0_GATE_DISABLE, 0);
Signature · 1 line
2.51.0