drm/print: make drm_err_printer() device specific by using drm_err()

With few users for drm_err_printer(), it's still feasible to convert it
to be device specific. Use drm_err() under the hood.

While at it, make the prefix optional.
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Luca Coelho <luciano.coelho@intel.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/2a9cdcfc1df44568078f7c131e2e7e0f7c94e97e.1705410327.git.jani.nikula@intel.com

drivers/gpu/drm/drm_print.c

@@ -191,7 +191,12 @@ EXPORT_SYMBOL(__drm_printfn_debug);
 
 void __drm_printfn_err(struct drm_printer *p, struct va_format *vaf)
 {
-	pr_err("*ERROR* %s %pV", p->prefix, vaf);
+	struct drm_device *drm = p->arg;
+
+	if (p->prefix)
+		drm_err(drm, "%s %pV", p->prefix, vaf);
+	else
+		drm_err(drm, "%pV", vaf);
 }
 EXPORT_SYMBOL(__drm_printfn_err);
 

drivers/gpu/drm/i915/gt/selftest_engine_heartbeat.c

@@ -122,7 +122,7 @@ static int __live_idle_pulse(struct intel_engine_cs *engine,
 	GEM_BUG_ON(!llist_empty(&engine->barrier_tasks));
 
 	if (engine_sync_barrier(engine)) {
-		struct drm_printer m = drm_err_printer("pulse");
+		struct drm_printer m = drm_err_printer(&engine->i915->drm, "pulse");
 
 		pr_err("%s: no heartbeat pulse?\n", engine->name);
 		intel_engine_dump(engine, &m, "%s", engine->name);
@@ -136,7 +136,7 @@ static int __live_idle_pulse(struct intel_engine_cs *engine,
 	pulse_unlock_wait(p); /* synchronize with the retirement callback */
 
 	if (!i915_active_is_idle(&p->active)) {
-		struct drm_printer m = drm_err_printer("pulse");
+		struct drm_printer m = drm_err_printer(&engine->i915->drm, "pulse");
 
 		pr_err("%s: heartbeat pulse did not flush idle tasks\n",
 		       engine->name);

drivers/gpu/drm/i915/selftests/i915_active.c

@@ -156,7 +156,7 @@ static int live_active_wait(void *arg)
 
 	__i915_active_wait(&active->base, TASK_UNINTERRUPTIBLE);
 	if (!READ_ONCE(active->retired)) {
-		struct drm_printer p = drm_err_printer(__func__);
+		struct drm_printer p = drm_err_printer(&i915->drm, __func__);
 
 		pr_err("i915_active not retired after waiting!\n");
 		i915_active_print(&active->base, &p);
@@ -189,7 +189,7 @@ static int live_active_retire(void *arg)
 		err = -EIO;
 
 	if (!READ_ONCE(active->retired)) {
-		struct drm_printer p = drm_err_printer(__func__);
+		struct drm_printer p = drm_err_printer(&i915->drm, __func__);
 
 		pr_err("i915_active not retired after flushing!\n");
 		i915_active_print(&active->base, &p);

include/drm/drm_print.h

@@ -35,6 +35,8 @@
 
 #include <drm/drm.h>
 
+struct drm_device;
+
 /* Do *not* use outside of drm_print.[ch]! */
 extern unsigned long __drm_debug;
 
@@ -235,16 +237,19 @@ static inline struct drm_printer drm_debug_printer(const char *prefix)
 }
 
 /**
- * drm_err_printer - construct a &drm_printer that outputs to pr_err()
- * @prefix: debug output prefix
+ * drm_err_printer - construct a &drm_printer that outputs to drm_err()
+ * @drm: the &struct drm_device pointer
+ * @prefix: debug output prefix, or NULL for no prefix
  *
  * RETURNS:
  * The &drm_printer object
  */
-static inline struct drm_printer drm_err_printer(const char *prefix)
+static inline struct drm_printer drm_err_printer(struct drm_device *drm,
+						 const char *prefix)
 {
 	struct drm_printer p = {
 		.printfn = __drm_printfn_err,
+		.arg = drm,
 		.prefix = prefix
 	};
 	return p;