drm/print: add drm_debug_enabled()

Add helper to check if a drm debug category is enabled. Convert drm core
to use it. No functional changes.

v2: Move unlikely() to drm_debug_enabled() (Eric)

v3: Keep unlikely() when combined with other conditions (Eric)

Cc: Eric Engestrom <eric@engestrom.ch>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Eric Engestrom <eric@engestrom.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191001140614.26909-1-jani.nikula@intel.com

drivers/gpu/drm/drm_atomic_uapi.c

@@ -1406,7 +1406,7 @@ int drm_mode_atomic_ioctl(struct drm_device *dev,
 	} else if (arg->flags & DRM_MODE_ATOMIC_NONBLOCK) {
 		ret = drm_atomic_nonblocking_commit(state);
 	} else {
-		if (unlikely(drm_debug & DRM_UT_STATE))
+		if (drm_debug_enabled(DRM_UT_STATE))
 			drm_atomic_print_state(state);
 
 		ret = drm_atomic_commit(state);

drivers/gpu/drm/drm_dp_mst_topology.c

@@ -1179,7 +1179,7 @@ static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
 		}
 	}
 out:
-	if (unlikely(ret == -EIO && drm_debug & DRM_UT_DP)) {
+	if (unlikely(ret == -EIO) && drm_debug_enabled(DRM_UT_DP)) {
 		struct drm_printer p = drm_debug_printer(DBG_PREFIX);
 
 		drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
@@ -2322,7 +2322,7 @@ static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
 	idx += tosend + 1;
 
 	ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
-	if (unlikely(ret && drm_debug & DRM_UT_DP)) {
+	if (unlikely(ret) && drm_debug_enabled(DRM_UT_DP)) {
 		struct drm_printer p = drm_debug_printer(DBG_PREFIX);
 
 		drm_printf(&p, "sideband msg failed to send\n");
@@ -2389,7 +2389,7 @@ static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
 	mutex_lock(&mgr->qlock);
 	list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
 
-	if (unlikely(drm_debug & DRM_UT_DP)) {
+	if (drm_debug_enabled(DRM_UT_DP)) {
 		struct drm_printer p = drm_debug_printer(DBG_PREFIX);
 
 		drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);

drivers/gpu/drm/drm_edid.c

@@ -1651,7 +1651,7 @@ static void connector_bad_edid(struct drm_connector *connector,
 {
 	int i;
 
-	if (connector->bad_edid_counter++ && !(drm_debug & DRM_UT_KMS))
+	if (connector->bad_edid_counter++ && !drm_debug_enabled(DRM_UT_KMS))
 		return;
 
 	dev_warn(connector->dev->dev,

drivers/gpu/drm/drm_edid_load.c

@@ -175,7 +175,7 @@ static void *edid_load(struct drm_connector *connector, const char *name,
 	u8 *edid;
 	int fwsize, builtin;
 	int i, valid_extensions = 0;
-	bool print_bad_edid = !connector->bad_edid_counter || (drm_debug & DRM_UT_KMS);
+	bool print_bad_edid = !connector->bad_edid_counter || drm_debug_enabled(DRM_UT_KMS);
 
 	builtin = match_string(generic_edid_name, GENERIC_EDIDS, name);
 	if (builtin >= 0) {

drivers/gpu/drm/drm_mipi_dbi.c

@@ -783,7 +783,7 @@ static int mipi_dbi_spi1e_transfer(struct mipi_dbi *dbi, int dc,
 	int i, ret;
 	u8 *dst;
 
-	if (drm_debug & DRM_UT_DRIVER)
+	if (drm_debug_enabled(DRM_UT_DRIVER))
 		pr_debug("[drm:%s] dc=%d, max_chunk=%zu, transfers:\n",
 			 __func__, dc, max_chunk);
 
@@ -907,7 +907,7 @@ static int mipi_dbi_spi1_transfer(struct mipi_dbi *dbi, int dc,
 	max_chunk = dbi->tx_buf9_len;
 	dst16 = dbi->tx_buf9;
 
-	if (drm_debug & DRM_UT_DRIVER)
+	if (drm_debug_enabled(DRM_UT_DRIVER))
 		pr_debug("[drm:%s] dc=%d, max_chunk=%zu, transfers:\n",
 			 __func__, dc, max_chunk);
 

drivers/gpu/drm/drm_print.c

@@ -262,7 +262,7 @@ void drm_dev_dbg(const struct device *dev, unsigned int category,
 	struct va_format vaf;
 	va_list args;
 
-	if (!(drm_debug & category))
+	if (!drm_debug_enabled(category))
 		return;
 
 	va_start(args, format);
@@ -285,7 +285,7 @@ void drm_dbg(unsigned int category, const char *format, ...)
 	struct va_format vaf;
 	va_list args;
 
-	if (!(drm_debug & category))
+	if (!drm_debug_enabled(category))
 		return;
 
 	va_start(args, format);

drivers/gpu/drm/drm_vblank.c

@@ -332,7 +332,7 @@ u64 drm_crtc_accurate_vblank_count(struct drm_crtc *crtc)
 	u64 vblank;
 	unsigned long flags;
 
-	WARN_ONCE(drm_debug & DRM_UT_VBL && !dev->driver->get_vblank_timestamp,
+	WARN_ONCE(drm_debug_enabled(DRM_UT_VBL) && !dev->driver->get_vblank_timestamp,
 		  "This function requires support for accurate vblank timestamps.");
 
 	spin_lock_irqsave(&dev->vblank_time_lock, flags);
@@ -706,7 +706,7 @@ bool drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
 	 */
 	*vblank_time = ktime_sub_ns(etime, delta_ns);
 
-	if ((drm_debug & DRM_UT_VBL) == 0)
+	if (!drm_debug_enabled(DRM_UT_VBL))
 		return true;
 
 	ts_etime = ktime_to_timespec64(etime);
@@ -1352,7 +1352,7 @@ void drm_vblank_restore(struct drm_device *dev, unsigned int pipe)
 	assert_spin_locked(&dev->vblank_time_lock);
 
 	vblank = &dev->vblank[pipe];
-	WARN_ONCE((drm_debug & DRM_UT_VBL) && !vblank->framedur_ns,
+	WARN_ONCE(drm_debug_enabled(DRM_UT_VBL) && !vblank->framedur_ns,
 		  "Cannot compute missed vblanks without frame duration\n");
 	framedur_ns = vblank->framedur_ns;
 

include/drm/drm_print.h

@@ -293,6 +293,11 @@ static inline struct drm_printer drm_err_printer(const char *prefix)
 #define DRM_UT_LEASE		0x80
 #define DRM_UT_DP		0x100
 
+static inline bool drm_debug_enabled(unsigned int category)
+{
+	return unlikely(drm_debug & category);
+}
+
 __printf(3, 4)
 void drm_dev_printk(const struct device *dev, const char *level,
 		    const char *format, ...);