drm/amd/display: Clean up debug macros

This patch simplifies the ASSERT*() and BREAK_TO_DEBUGGER() macros:
- Move the dependency check of CONFIG_KGDB into Kconfig
- Unify the kgdb_breakpoint() call
- Drop the non-existing CONFIG_HAVE_KGDB

Also align the behavior of ASSERT() macro in both cases with and
without CONFIG_DEBUG_KERNEL_DC.

Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/Kconfig

@@ -42,6 +42,7 @@ config DRM_AMD_DC_SI
 config DEBUG_KERNEL_DC
 	bool "Enable kgdb break in DC"
 	depends on DRM_AMD_DC
+	depends on KGDB
 	help
 	  Choose this option if you want to hit kdgb_break in assert.
 

drivers/gpu/drm/amd/display/dc/os_types.h

@@ -94,36 +94,27 @@
  * general debug capabilities
  *
  */
-#if defined(CONFIG_DEBUG_KERNEL_DC) && (defined(CONFIG_HAVE_KGDB) || defined(CONFIG_KGDB))
-#define ASSERT_CRITICAL(expr) do {	\
-	if (WARN_ON(!(expr))) { \
-		kgdb_breakpoint(); \
-	} \
-} while (0)
+#ifdef CONFIG_DEBUG_KERNEL_DC
+#define dc_breakpoint()		kgdb_breakpoint()
 #else
-#define ASSERT_CRITICAL(expr) do {	\
-	if (WARN_ON(!(expr))) { \
-		; \
-	} \
-} while (0)
+#define dc_breakpoint()		do {} while (0)
 #endif
 
-#if defined(CONFIG_DEBUG_KERNEL_DC)
-#define ASSERT(expr) ASSERT_CRITICAL(expr)
+#define ASSERT_CRITICAL(expr) do {		\
+		if (WARN_ON(!(expr)))		\
+			dc_breakpoint();	\
+	} while (0)
 
-#else
-#define ASSERT(expr) WARN_ON_ONCE(!(expr))
-#endif
+#define ASSERT(expr) do {			\
+		if (WARN_ON_ONCE(!(expr)))	\
+			dc_breakpoint();	\
+	} while (0)
 
-#if defined(CONFIG_DEBUG_KERNEL_DC) && (defined(CONFIG_HAVE_KGDB) || defined(CONFIG_KGDB))
 #define BREAK_TO_DEBUGGER() \
 	do { \
 		DRM_DEBUG_DRIVER("%s():%d\n", __func__, __LINE__); \
-		kgdb_breakpoint(); \
+		dc_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__); \