linux-kernel - [PATCH AUTOSEL 6.8 24/98] drm/amd/display: Disable idle reallow as part of command/gpint execution

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Date: Fri, 29 Mar 2024 08:36:55 -0400
From: Sasha Levin <sashal@...nel.org>
To: linux-kernel@...r.kernel.org,
	stable@...r.kernel.org
Cc: Nicholas Kazlauskas <nicholas.kazlauskas@....com>,
	Ovidiu Bunea <ovidiu.bunea@....com>,
	Hamza Mahfooz <hamza.mahfooz@....com>,
	Alex Deucher <alexander.deucher@....com>,
	Sasha Levin <sashal@...nel.org>,
	harry.wentland@....com,
	sunpeng.li@....com,
	Rodrigo.Siqueira@....com,
	christian.koenig@....com,
	Xinhui.Pan@....com,
	airlied@...il.com,
	daniel@...ll.ch,
	aric.cyr@....com,
	jun.lei@....com,
	alvin.lee2@....com,
	Qingqing.Zhuo@....com,
	chiahsuan.chung@....com,
	george.shen@....com,
	dillon.varone@....com,
	wayne.lin@....com,
	duncan.ma@....com,
	samson.tam@....com,
	srinivasan.shanmugam@....com,
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	cruise.hung@....com,
	charlene.liu@....com,
	ahmed.ahmed@....com,
	wenjing.liu@....com,
	amd-gfx@...ts.freedesktop.org,
	dri-devel@...ts.freedesktop.org
Subject: [PATCH AUTOSEL 6.8 24/98] drm/amd/display: Disable idle reallow as part of command/gpint execution

From: Nicholas Kazlauskas <nicholas.kazlauskas@....com>

[ Upstream commit 6226a5aa77370329e01ee8abe50a95e60618ce97 ]

[Why]
Workaroud for a race condition where DMCUB is in the process of
committing to IPS1 during the handshake causing us to miss the
transition into IPS2 and touch the INBOX1 RPTR causing a HW hang.

[How]
Disable the reallow to ensure that we have enough of a gap between entry
and exit and we're not seeing back-to-back wake_and_executes.

Reviewed-by: Ovidiu Bunea <ovidiu.bunea@....com>
Acked-by: Hamza Mahfooz <hamza.mahfooz@....com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@....com>
Signed-off-by: Alex Deucher <alexander.deucher@....com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/gpu/drm/amd/display/dc/dc.h                           | 1 +
 drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c                  | 4 ++--
 .../gpu/drm/amd/display/dc/resource/dcn35/dcn35_resource.c    | 1 +
 3 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h
index c9317ea0258ea..b46c894672b60 100644
--- a/drivers/gpu/drm/amd/display/dc/dc.h
+++ b/drivers/gpu/drm/amd/display/dc/dc.h
@@ -987,6 +987,7 @@ struct dc_debug_options {
 	bool psp_disabled_wa;
 	unsigned int ips2_eval_delay_us;
 	unsigned int ips2_entry_delay_us;
+	bool disable_dmub_reallow_idle;
 	bool disable_timeout;
 	bool disable_extblankadj;
 	unsigned int static_screen_wait_frames;
diff --git a/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c b/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c
index 363d522603a21..9084b320849a6 100644
--- a/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c
+++ b/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c
@@ -1364,7 +1364,7 @@ bool dc_wake_and_execute_dmub_cmd_list(const struct dc_context *ctx, unsigned in
 	else
 		result = dm_execute_dmub_cmd(ctx, cmd, wait_type);
 
-	if (result && reallow_idle)
+	if (result && reallow_idle && !ctx->dc->debug.disable_dmub_reallow_idle)
 		dc_dmub_srv_apply_idle_power_optimizations(ctx->dc, true);
 
 	return result;
@@ -1413,7 +1413,7 @@ bool dc_wake_and_execute_gpint(const struct dc_context *ctx, enum dmub_gpint_com
 
 	result = dc_dmub_execute_gpint(ctx, command_code, param, response, wait_type);
 
-	if (result && reallow_idle)
+	if (result && reallow_idle && !ctx->dc->debug.disable_dmub_reallow_idle)
 		dc_dmub_srv_apply_idle_power_optimizations(ctx->dc, true);
 
 	return result;
diff --git a/drivers/gpu/drm/amd/display/dc/resource/dcn35/dcn35_resource.c b/drivers/gpu/drm/amd/display/dc/resource/dcn35/dcn35_resource.c
index 5fdcda8f86026..ff17fce44eb1d 100644
--- a/drivers/gpu/drm/amd/display/dc/resource/dcn35/dcn35_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/resource/dcn35/dcn35_resource.c
@@ -782,6 +782,7 @@ static const struct dc_debug_options debug_defaults_drv = {
 	.psp_disabled_wa = true,
 	.ips2_eval_delay_us = 2000,
 	.ips2_entry_delay_us = 800,
+	.disable_dmub_reallow_idle = true,
 	.static_screen_wait_frames = 2,
 };
 
-- 
2.43.0