From 7b9902dca02a1a9b88c7396bc69e73629ecf4769 Mon Sep 17 00:00:00 2001
From: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Date: Fri, 22 May 2020 14:03:26 -0400
Subject: drm/amd/display: Make BREAK_TO_DEBUGGER() a debug print
Git-commit: 1aad7078191116f8a363466fcf461f2325c5def2
Patch-mainline: v5.9-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322

[Why]
Warnings in the kernel are generally treated as errors.

The BREAK_TO_DEBUGGER macro is not a critical error or warning, but
rather intended for developer use to help investigate behavior and
sequences for other issues.

We do still make use of DC_ERROR/ASSERT(0) in various places in the
code for things that are genuine issues.

Since most developers don't actually KGDB while debugging the kernel
these essentially would have no value on their own since the KGDB
breakpoint wouldn't trigger - ASSERT(0) was used as a shortcut to get
a stacktrace.

[How]
Turn it into a DRM_DEBUG_DRIVER print instead. We unfortunately lose
the stacktrace, but we still do retain some of the useful debug
information this offers by having at least the function and line
number loggable.

If KGDB is supported in the kernel this will still trigger a real
breakpoint as well.

Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Leo Li <sunpeng.li@amd.com>
Cc: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Cc: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/amd/display/dc/os_types.h | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/os_types.h b/drivers/gpu/drm/amd/display/dc/os_types.h
index 6d7bca562eec..604ceb6c0375 100644
--- a/drivers/gpu/drm/amd/display/dc/os_types.h
+++ b/drivers/gpu/drm/amd/display/dc/os_types.h
@@ -111,7 +111,15 @@
 #define ASSERT(expr) WARN_ON_ONCE(!(expr))
 #endif
 
-#define BREAK_TO_DEBUGGER() ASSERT(0)
+#if defined(CONFIG_HAVE_KGDB) || defined(CONFIG_KGDB)
+#define BREAK_TO_DEBUGGER() \
+	do { \
+		DRM_DEBUG_DRIVER("%s():%d\n", __func__, __LINE__); \
+		kgdb_breakpoint(); \
+	} while (0)
+#else
+#define BREAK_TO_DEBUGGER() DRM_DEBUG_DRIVER("%s():%d\n", __func__, __LINE__)
+#endif
 
 #define DC_ERR(...)  do { \
 	dm_error(__VA_ARGS__); \
-- 
2.29.2