[PATCH v2 3/3] drm: Add self_refresh_state debugfs entry

[Sean Paul]

From: Sean Paul <seanpaul at chromium.org>

This patch adds a debugfs entry to surface the entry and exit times as
well as the calculated delay.

Suggested-by: Daniel Vetter <daniel at ffwll.ch>
Signed-off-by: Sean Paul <seanpaul at chromium.org>

Changes in v2:
- Added to the set
---

Wasn't too sure how to initialize this, as calling the helper function
from drm_debugfs.c seemed... wrong. However there weren't any other
compelling solutions, so I figured I'd post this and learn something
new.



 drivers/gpu/drm/drm_debugfs.c             | 10 +++++
 drivers/gpu/drm/drm_self_refresh_helper.c | 55 ++++++++++++++++++++++-
 include/drm/drm_self_refresh_helper.h     |  6 +++
 3 files changed, 69 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c
index eab0f2687cd6..175c2451ae72 100644
--- a/drivers/gpu/drm/drm_debugfs.c
+++ b/drivers/gpu/drm/drm_debugfs.c
@@ -38,6 +38,9 @@
 #include <drm/drm_edid.h>
 #include <drm/drm_file.h>
 #include <drm/drm_gem.h>
+#if defined(CONFIG_DRM_KMS_HELPER)
+#include <drm/drm_self_refresh_helper.h>
+#endif
 
 #include "drm_crtc_internal.h"
 #include "drm_internal.h"
@@ -231,6 +234,13 @@ int drm_debugfs_init(struct drm_minor *minor, int minor_id,
 			DRM_ERROR("Failed to create atomic debugfs files\n");
 			return ret;
 		}
+#if defined(CONFIG_DRM_KMS_HELPER)
+		ret = drm_self_refresh_debugfs_init(minor);
+		if (ret) {
+			DRM_ERROR("Failed to init self refresh debugfs\n");
+			return ret;
+		}
+#endif
 	}
 
 	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
diff --git a/drivers/gpu/drm/drm_self_refresh_helper.c b/drivers/gpu/drm/drm_self_refresh_helper.c
index 68f4765a5896..e7544ae1e47b 100644
--- a/drivers/gpu/drm/drm_self_refresh_helper.c
+++ b/drivers/gpu/drm/drm_self_refresh_helper.c
@@ -14,7 +14,9 @@
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_connector.h>
 #include <drm/drm_crtc.h>
+#include <drm/drm_debugfs.h>
 #include <drm/drm_device.h>
+#include <drm/drm_file.h>
 #include <drm/drm_mode_config.h>
 #include <drm/drm_modeset_lock.h>
 #include <drm/drm_print.h>
@@ -167,6 +169,16 @@ void drm_self_refresh_helper_update_avg_times(struct drm_atomic_state *state,
 }
 EXPORT_SYMBOL(drm_self_refresh_helper_update_avg_times);
 
+static unsigned int
+drm_self_refresh_calc_idle_delay(struct drm_self_refresh_data *sr_data)
+{
+	if (WARN_ON(!mutex_is_locked(&sr_data->avg_mutex)))
+	    return SELF_REFRESH_AVG_SEED_MS * 4;
+
+	return (ewma_psr_time_read(&sr_data->entry_avg_ms) +
+		ewma_psr_time_read(&sr_data->exit_avg_ms)) * 2;
+}
+
 /**
  * drm_self_refresh_helper_alter_state - Alters the atomic state for SR exit
  * @state: the state currently being checked
@@ -209,8 +221,7 @@ void drm_self_refresh_helper_alter_state(struct drm_atomic_state *state)
 			continue;
 
 		mutex_lock(&sr_data->avg_mutex);
-		delay = (ewma_psr_time_read(&sr_data->entry_avg_ms) +
-			 ewma_psr_time_read(&sr_data->exit_avg_ms)) * 2;
+		delay = drm_self_refresh_calc_idle_delay(sr_data);
 		mutex_unlock(&sr_data->avg_mutex);
 
 		mod_delayed_work(system_wq, &sr_data->entry_work,
@@ -275,3 +286,43 @@ void drm_self_refresh_helper_cleanup(struct drm_crtc *crtc)
 	kfree(sr_data);
 }
 EXPORT_SYMBOL(drm_self_refresh_helper_cleanup);
+
+#ifdef CONFIG_DEBUG_FS
+
+static int drm_self_refresh_debugfs_state(struct seq_file *m, void *data)
+{
+	struct drm_info_node *node = (struct drm_info_node *) m->private;
+	struct drm_device *dev = node->minor->dev;
+	struct drm_printer p = drm_seq_file_printer(m);
+	struct drm_crtc *crtc;
+
+	drm_for_each_crtc(crtc, dev) {
+		struct drm_self_refresh_data *sr_data = crtc->self_refresh_data;
+		if (!sr_data)
+			continue;
+
+		mutex_lock(&sr_data->avg_mutex);
+		drm_printf(&p, "crtc[%u]: %s\n", crtc->base.id, crtc->name);
+		drm_printf(&p, "\tentry_avg_ms=%lu\n",
+			   ewma_psr_time_read(&sr_data->entry_avg_ms));
+		drm_printf(&p, "\texit_avg_ms=%lu\n",
+			   ewma_psr_time_read(&sr_data->exit_avg_ms));
+		drm_printf(&p, "\tidle_delay=%u\n",
+			   drm_self_refresh_calc_idle_delay(sr_data));
+		mutex_unlock(&sr_data->avg_mutex);
+	}
+	return 0;
+}
+
+static const struct drm_info_list drm_atomic_debugfs_list[] = {
+	{"self_refresh_state", drm_self_refresh_debugfs_state, 0},
+};
+
+int drm_self_refresh_debugfs_init(struct drm_minor *minor)
+{
+	return drm_debugfs_create_files(drm_atomic_debugfs_list,
+			ARRAY_SIZE(drm_atomic_debugfs_list),
+			minor->debugfs_root, minor);
+}
+EXPORT_SYMBOL(drm_self_refresh_debugfs_init);
+#endif
diff --git a/include/drm/drm_self_refresh_helper.h b/include/drm/drm_self_refresh_helper.h
index 5b79d253fb46..779f81e035f1 100644
--- a/include/drm/drm_self_refresh_helper.h
+++ b/include/drm/drm_self_refresh_helper.h
@@ -17,4 +17,10 @@ void drm_self_refresh_helper_update_avg_times(struct drm_atomic_state *state,
 
 int drm_self_refresh_helper_init(struct drm_crtc *crtc);
 void drm_self_refresh_helper_cleanup(struct drm_crtc *crtc);
+
+#ifdef CONFIG_DEBUG_FS
+struct drm_minor;
+int drm_self_refresh_debugfs_init(struct drm_minor *minor);
+#endif
+
 #endif
-- 
Sean Paul, Software Engineer, Google / Chromium OS