[PATCH v4] drm/xe: Fix build error for XE_IOCTL_DBG macro

[Gyeyoung Baek]

if CONFIG_DRM_USE_DYNAMIC_DEBUG is set,
'drm_dbg' function is replaced with '__dynamic_func_call_cls',
which is replaced with a do while statement.
so in the previous code, there are the following build errors.

include/linux/dynamic_debug.h:221:58: error: expected expression before ‘do’
  221 | #define __dynamic_func_call_cls(id, cls, fmt, func, ...) do {   \
      |                                                          ^~
include/linux/dynamic_debug.h:248:9: note: in expansion of macro ‘__dynamic_func_call_cls’
  248 |         __dynamic_func_call_cls(__UNIQUE_ID(ddebug), cls, fmt, func, ##__VA_ARGS__)
      |         ^~~~~~~~~~~~~~~~~~~~~~~
include/drm/drm_print.h:425:9: note: in expansion of macro ‘_dynamic_func_call_cls’
  425 |         _dynamic_func_call_cls(cat, fmt, __drm_dev_dbg,         \
      |         ^~~~~~~~~~~~~~~~~~~~~~
include/drm/drm_print.h:504:9: note: in expansion of macro ‘drm_dev_dbg’
  504 |         drm_dev_dbg((drm) ? (drm)->dev : NULL, DRM_UT_DRIVER, fmt, ##__VA_ARGS__)
      |         ^~~~~~~~~~~
include/drm/drm_print.h:522:33: note: in expansion of macro ‘drm_dbg_driver’
  522 | #define drm_dbg(drm, fmt, ...)  drm_dbg_driver(drm, fmt, ##__VA_ARGS__)
      |                                 ^~~~~~~~~~~~~~
drivers/gpu/drm/xe/xe_macros.h:14:21: note: in expansion of macro ‘drm_dbg’
   14 |         ((cond) && (drm_dbg(&(xe)->drm, \
      |                     ^~~~~~~
drivers/gpu/drm/xe/xe_bo.c:2029:13: note: in expansion of macro ‘XE_IOCTL_DBG’
 2029 |         if (XE_IOCTL_DBG(xe, !gem_obj))

the problem is that,
XE_IOCTL_DBG uses this function for conditional expr.

so I fix the expr to be compatible with the do while statement,
by referring to "https://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html".

v2: I modified this to print when only cond is true.
v3: Modify to evaluate cond only once.
v4: There was a mistake in v3, send this again.

Signed-off-by: Gyeyoung Baek <gye976 at gmail.com>
---
 drivers/gpu/drm/xe/xe_macros.h | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_macros.h b/drivers/gpu/drm/xe/xe_macros.h
index daf56c846d03..51ac8faa8975 100644
--- a/drivers/gpu/drm/xe/xe_macros.h
+++ b/drivers/gpu/drm/xe/xe_macros.h
@@ -10,9 +10,13 @@
 
 #define XE_WARN_ON WARN_ON
 
-#define XE_IOCTL_DBG(xe, cond) \
-	((cond) && (drm_dbg(&(xe)->drm, \
-			    "Ioctl argument check failed at %s:%d: %s", \
-			    __FILE__, __LINE__, #cond), 1))
+#define XE_IOCTL_DBG(xe, cond) ({					\
+	int cond__ = !!(cond);						\
+	if (cond__)                                           		\
+		drm_dbg(&(xe)->drm,                                    	\
+			"Ioctl argument check failed at %s:%d: %s",	\
+			__FILE__, __LINE__, #cond);                    	\
+	cond__;                                                        	\
+})
 
 #endif
-- 
2.34.1