[PATCH 13/13] drm_print: use DEFINE_DYNAMIC_DEBUG_CLASSBITS for drm.debug

From: Jim Cromie
Date: Tue Mar 01 2022 - 11:47:38 EST


if CONFIG_DRM_USE_DYNAMIC_DEBUG=y, use new macro to create the sysfs
bitmap to control drm.debug callsites.

DEFINE_DYNAMIC_DEBUG_CLASSBITS( debug, __drm_debug, "p",
"drm.debug - control summary",
/* inline vector of _ddebug.class_id's to be controlled, max 14 vals */
DRM_UT_CORE,
DRM_UT_DRIVER,
DRM_UT_KMS,
DRM_UT_PRIME,
DRM_UT_ATOMIC,
DRM_UT_VBL,
DRM_UT_STATE,
DRM_UT_LEASE,
DRM_UT_DP,
DRM_UT_DRMRES );

NOTES:

The @_flgs used here is "p", so this bitmap enables input to syslog
only, matching legacy behavior.

Also, no "fmlt" decorator flags are used here; that is discouraged, as
it then toggles those flags along with the "p". This would overwrite
any customizations a user added since the sysfs-knob was last used.
Still, there may be cases/reasons.

_ddebug.class_id is uint:4, values 0-14 are valid. 15 is reserved for
non-classified callsites (regular pr_debugs). Using it terminates the
scan, don't use it halfway through your list.

Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx>
---
drivers/gpu/drm/drm_print.c | 20 ++++++++++++++++++--
include/drm/drm_print.h | 4 ++--
2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/drm_print.c b/drivers/gpu/drm/drm_print.c
index c9b2a2ab0d3d..d916daa384e5 100644
--- a/drivers/gpu/drm/drm_print.c
+++ b/drivers/gpu/drm/drm_print.c
@@ -38,7 +38,7 @@
* __drm_debug: Enable debug output.
* Bitmask of DRM_UT_x. See include/drm/drm_print.h for details.
*/
-unsigned int __drm_debug;
+unsigned long __drm_debug;
EXPORT_SYMBOL(__drm_debug);

MODULE_PARM_DESC(debug, "Enable debug output, where each bit enables a debug category.\n"
@@ -50,7 +50,23 @@ MODULE_PARM_DESC(debug, "Enable debug output, where each bit enables a debug cat
"\t\tBit 5 (0x20) will enable VBL messages (vblank code)\n"
"\t\tBit 7 (0x80) will enable LEASE messages (leasing code)\n"
"\t\tBit 8 (0x100) will enable DP messages (displayport code)");
-module_param_named(debug, __drm_debug, int, 0600);
+
+#if !defined(CONFIG_DRM_USE_DYNAMIC_DEBUG)
+module_param_named(debug, __drm_debug, ulong, 0600);
+#else
+DEFINE_DYNAMIC_DEBUG_CLASSBITS(debug, __drm_debug, "p",
+ "enable drm.debug categories - 1 bit per category",
+ DRM_UT_CORE,
+ DRM_UT_DRIVER,
+ DRM_UT_KMS,
+ DRM_UT_PRIME,
+ DRM_UT_ATOMIC,
+ DRM_UT_VBL,
+ DRM_UT_STATE,
+ DRM_UT_LEASE,
+ DRM_UT_DP,
+ DRM_UT_DRMRES);
+#endif

void __drm_puts_coredump(struct drm_printer *p, const char *str)
{
diff --git a/include/drm/drm_print.h b/include/drm/drm_print.h
index 13d52b60f388..419140bf992d 100644
--- a/include/drm/drm_print.h
+++ b/include/drm/drm_print.h
@@ -36,7 +36,7 @@
#include <drm/drm.h>

/* Do *not* use outside of drm_print.[ch]! */
-extern unsigned int __drm_debug;
+extern unsigned long __drm_debug;

/**
* DOC: print
@@ -527,7 +527,7 @@ __printf(1, 2)
void __drm_err(const char *format, ...);

#if !defined(CONFIG_DRM_USE_DYNAMIC_DEBUG)
-#define __drm_dbg(fmt, ...) ___drm_dbg(NULL, fmt, ##__VA_ARGS__)
+#define __drm_dbg(cat, fmt, ...) ___drm_dbg(NULL, cat, fmt, ##__VA_ARGS__)
#else
#define __drm_dbg(cat, fmt, ...) \
_dynamic_func_call_cls(cat, fmt, ___drm_dbg, \
--
2.35.1