FAILED: patch "[PATCH] drm/amd/display: Prevent Gating DTBCLK before It Is Properly" failed to apply to 6.17-stable tree

FAILED: patch "[PATCH] drm/amd/display: Prevent Gating DTBCLK before It Is Properly" failed to apply to 6.17-stable tree

[gregkh]

The patch below does not apply to the 6.17-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 <stable@vger.kernel.org>.

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-6.17.y
git checkout FETCH_HEAD
git cherry-pick -x cfa0904a35fd0231f4d05da0190f0a22ed881cce
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025112424-handball-smolder-0f15@gregkh' --subject-prefix 'PATCH 6.17.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 <Jerry.Zuo@amd.com>
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 <charlene.liu@amd.com>
Reviewed-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Fangzhi Zuo <Jerry.Zuo@amd.com>
Signed-off-by: Roman Li <roman.li@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit d04eb0c402780ca037b62a6aecf23b863545ebca)
Cc: stable@vger.kernel.org

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 b11383fba35f..1eb04772f5da 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
@@ -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;
 			}
diff --git a/drivers/gpu/drm/amd/display/dc/dccg/dcn35/dcn35_dccg.c b/drivers/gpu/drm/amd/display/dc/dccg/dcn35/dcn35_dccg.c
index de6d62401362..c899c09ea31b 100644
--- a/drivers/gpu/drm/amd/display/dc/dccg/dcn35/dcn35_dccg.c
+++ b/drivers/gpu/drm/amd/display/dc/dccg/dcn35/dcn35_dccg.c
@@ -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);

[PATCH 6.17.y 1/2] drm/amd/display: Insert dccg log for easy debug

[Sasha Levin]

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

[ Upstream commit 35bcc9168f3ce6416cbf3f776758be0937f84cb3 ]

[why]
Log for sequence tracking

Reviewed-by: Ovidiu (Ovi) Bunea <ovidiu.bunea@amd.com>
Reviewed-by: Yihan Zhu <yihan.zhu@amd.com>
Signed-off-by: Charlene Liu <Charlene.Liu@amd.com>
Signed-off-by: Ivan Lipski <ivan.lipski@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Stable-dep-of: cfa0904a35fd ("drm/amd/display: Prevent Gating DTBCLK before It Is Properly Latched")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 .../amd/display/dc/dccg/dcn35/dcn35_dccg.c    | 24 ++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dccg/dcn35/dcn35_dccg.c b/drivers/gpu/drm/amd/display/dc/dccg/dcn35/dcn35_dccg.c
index 0ce9489ac6b72..de6d62401362e 100644
--- a/drivers/gpu/drm/amd/display/dc/dccg/dcn35/dcn35_dccg.c
+++ b/drivers/gpu/drm/amd/display/dc/dccg/dcn35/dcn35_dccg.c
@@ -39,6 +39,7 @@
 
 #define CTX \
 	dccg_dcn->base.ctx
+#include "logger_types.h"
 #define DC_LOGGER \
 	dccg->ctx->logger
 
@@ -1136,7 +1137,7 @@ 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);
 
 }
 
@@ -1406,6 +1407,10 @@ 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:
@@ -1431,6 +1436,8 @@ 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);
 	}
 }
 
@@ -1475,6 +1482,8 @@ 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);
 }
 
 
@@ -1514,6 +1523,8 @@ 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);
 }
 
 
@@ -1553,7 +1564,7 @@ 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);
 
 }
 
@@ -1626,6 +1637,8 @@ 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(
@@ -1673,6 +1686,7 @@ 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(
@@ -1731,6 +1745,7 @@ static void dccg35_disable_symclk32_se(
 		BREAK_TO_DEBUGGER();
 		return;
 	}
+
 }
 
 static void dccg35_init_cb(struct dccg *dccg)
@@ -1738,7 +1753,6 @@ 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;
@@ -1753,6 +1767,8 @@ 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)
@@ -1765,6 +1781,8 @@ 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);
 		}
 
 /*
-- 
2.51.0

[PATCH 6.17.y 2/2] drm/amd/display: Prevent Gating DTBCLK before It Is Properly Latched

[Sasha Levin]

From: Fangzhi Zuo <Jerry.Zuo@amd.com>

[ 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 <charlene.liu@amd.com>
Reviewed-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Fangzhi Zuo <Jerry.Zuo@amd.com>
Signed-off-by: Roman Li <roman.li@amd.com>
Tested-by: Dan Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit d04eb0c402780ca037b62a6aecf23b863545ebca)
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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(-)

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 0e638bc6bf77b..4e4390d565473 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
@@ -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;
 			}
diff --git a/drivers/gpu/drm/amd/display/dc/dccg/dcn35/dcn35_dccg.c b/drivers/gpu/drm/amd/display/dc/dccg/dcn35/dcn35_dccg.c
index de6d62401362e..c899c09ea31b8 100644
--- a/drivers/gpu/drm/amd/display/dc/dccg/dcn35/dcn35_dccg.c
+++ b/drivers/gpu/drm/amd/display/dc/dccg/dcn35/dcn35_dccg.c
@@ -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);
-- 
2.51.0