[PATCH v3 07/12] drm/client: Move suspend/resume into DRM client callbacks

[Thomas Zimmermann <tzimmermann@suse.de>]

Suspend and resume is still tied to fbdev emulation. Modeset helpers
and several drivers call drm_fb_helper_set_suspend_unlocked() to inform
the fbdev client about suspend/resume events.

To make it work with arbitrary clients, add per-client callback
functions for suspend and resume. Implement them for fbdev emulation
with the existing drm_fb_helper_set_suspend_unlocked(). Then update
DRM's modeset helpers to call the new interface.

Clients that are not fbdev can now implement suspend/resume to their
requirements.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/drm_client_event.c   | 60 ++++++++++++++++++++++++++++
 drivers/gpu/drm/drm_fbdev_client.c   | 30 +++++++++++++-
 drivers/gpu/drm/drm_modeset_helper.c | 14 ++++---
 include/drm/drm_client.h             | 35 ++++++++++++++++
 include/drm/drm_client_event.h       |  2 +
 5 files changed, 133 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/drm_client_event.c b/drivers/gpu/drm/drm_client_event.c
index d13d44320c5c..c52e93643672 100644
--- a/drivers/gpu/drm/drm_client_event.c
+++ b/drivers/gpu/drm/drm_client_event.c
@@ -107,6 +107,66 @@ void drm_client_dev_restore(struct drm_device *dev)
 	mutex_unlock(&dev->clientlist_mutex);
 }
 
+static int drm_client_suspend(struct drm_client_dev *client, bool holds_console_lock)
+{
+	struct drm_device *dev = client->dev;
+	int ret = 0;
+
+	if (drm_WARN_ON_ONCE(dev, client->suspended))
+		return 0;
+
+	if (client->funcs && client->funcs->suspend)
+		ret = client->funcs->suspend(client, holds_console_lock);
+	drm_dbg_kms(dev, "%s: ret=%d\n", client->name, ret);
+
+	client->suspended = true;
+
+	return ret;
+}
+
+void drm_client_dev_suspend(struct drm_device *dev, bool holds_console_lock)
+{
+	struct drm_client_dev *client;
+
+	mutex_lock(&dev->clientlist_mutex);
+	list_for_each_entry(client, &dev->clientlist, list) {
+		if (!client->suspended)
+			drm_client_suspend(client, holds_console_lock);
+	}
+	mutex_unlock(&dev->clientlist_mutex);
+}
+EXPORT_SYMBOL(drm_client_dev_suspend);
+
+static int drm_client_resume(struct drm_client_dev *client, bool holds_console_lock)
+{
+	struct drm_device *dev = client->dev;
+	int ret = 0;
+
+	if (drm_WARN_ON_ONCE(dev, !client->suspended))
+		return 0;
+
+	if (client->funcs && client->funcs->resume)
+		ret = client->funcs->resume(client, holds_console_lock);
+	drm_dbg_kms(dev, "%s: ret=%d\n", client->name, ret);
+
+	client->suspended = false;
+
+	return ret;
+}
+
+void drm_client_dev_resume(struct drm_device *dev, bool holds_console_lock)
+{
+	struct drm_client_dev *client;
+
+	mutex_lock(&dev->clientlist_mutex);
+	list_for_each_entry(client, &dev->clientlist, list) {
+		if  (client->suspended)
+			drm_client_resume(client, holds_console_lock);
+	}
+	mutex_unlock(&dev->clientlist_mutex);
+}
+EXPORT_SYMBOL(drm_client_dev_resume);
+
 #ifdef CONFIG_DEBUG_FS
 static int drm_client_debugfs_internal_clients(struct seq_file *m, void *data)
 {
diff --git a/drivers/gpu/drm/drm_fbdev_client.c b/drivers/gpu/drm/drm_fbdev_client.c
index a09382afe2fb..246fb63ab250 100644
--- a/drivers/gpu/drm/drm_fbdev_client.c
+++ b/drivers/gpu/drm/drm_fbdev_client.c
@@ -61,11 +61,37 @@ static int drm_fbdev_client_hotplug(struct drm_client_dev *client)
 	return ret;
 }
 
+static int drm_fbdev_client_suspend(struct drm_client_dev *client, bool holds_console_lock)
+{
+	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
+
+	if (holds_console_lock)
+		drm_fb_helper_set_suspend(fb_helper, true);
+	else
+		drm_fb_helper_set_suspend_unlocked(fb_helper, true);
+
+	return 0;
+}
+
+static int drm_fbdev_client_resume(struct drm_client_dev *client, bool holds_console_lock)
+{
+	struct drm_fb_helper *fb_helper = drm_fb_helper_from_client(client);
+
+	if (holds_console_lock)
+		drm_fb_helper_set_suspend(fb_helper, false);
+	else
+		drm_fb_helper_set_suspend_unlocked(fb_helper, false);
+
+	return 0;
+}
+
 static const struct drm_client_funcs drm_fbdev_client_funcs = {
 	.owner		= THIS_MODULE,
 	.unregister	= drm_fbdev_client_unregister,
 	.restore	= drm_fbdev_client_restore,
 	.hotplug	= drm_fbdev_client_hotplug,
+	.suspend	= drm_fbdev_client_suspend,
+	.resume		= drm_fbdev_client_resume,
 };
 
 /**
@@ -76,8 +102,8 @@ static const struct drm_client_funcs drm_fbdev_client_funcs = {
  *
  * This function sets up fbdev emulation. Restore, hotplug events and
  * teardown are all taken care of. Drivers that do suspend/resume need
- * to call drm_fb_helper_set_suspend_unlocked() themselves. Simple
- * drivers might use drm_mode_config_helper_suspend().
+ * to call drm_client_dev_suspend() and drm_client_dev_resume() by
+ * themselves. Simple drivers might use drm_mode_config_helper_suspend().
  *
  * This function is safe to call even when there are no connectors present.
  * Setup will be retried on the next hotplug event.
diff --git a/drivers/gpu/drm/drm_modeset_helper.c b/drivers/gpu/drm/drm_modeset_helper.c
index 2c582020cb42..5565464c1734 100644
--- a/drivers/gpu/drm/drm_modeset_helper.c
+++ b/drivers/gpu/drm/drm_modeset_helper.c
@@ -21,7 +21,7 @@
  */
 
 #include <drm/drm_atomic_helper.h>
-#include <drm/drm_fb_helper.h>
+#include <drm/drm_client_event.h>
 #include <drm/drm_fourcc.h>
 #include <drm/drm_framebuffer.h>
 #include <drm/drm_modeset_helper.h>
@@ -185,7 +185,7 @@ EXPORT_SYMBOL(drm_crtc_init);
  * Zero on success, negative error code on error.
  *
  * See also:
- * drm_kms_helper_poll_disable() and drm_fb_helper_set_suspend_unlocked().
+ * drm_kms_helper_poll_disable() and drm_client_dev_suspend().
  */
 int drm_mode_config_helper_suspend(struct drm_device *dev)
 {
@@ -199,10 +199,11 @@ int drm_mode_config_helper_suspend(struct drm_device *dev)
 	if (dev->mode_config.poll_enabled)
 		drm_kms_helper_poll_disable(dev);
 
-	drm_fb_helper_set_suspend_unlocked(dev->fb_helper, 1);
+	drm_client_dev_suspend(dev, false);
 	state = drm_atomic_helper_suspend(dev);
 	if (IS_ERR(state)) {
-		drm_fb_helper_set_suspend_unlocked(dev->fb_helper, 0);
+		drm_client_dev_resume(dev, false);
+
 		/*
 		 * Don't enable polling if it was never initialized
 		 */
@@ -230,7 +231,7 @@ EXPORT_SYMBOL(drm_mode_config_helper_suspend);
  * Zero on success, negative error code on error.
  *
  * See also:
- * drm_fb_helper_set_suspend_unlocked() and drm_kms_helper_poll_enable().
+ * drm_client_dev_resume() and drm_kms_helper_poll_enable().
  */
 int drm_mode_config_helper_resume(struct drm_device *dev)
 {
@@ -247,7 +248,8 @@ int drm_mode_config_helper_resume(struct drm_device *dev)
 		DRM_ERROR("Failed to resume (%d)\n", ret);
 	dev->mode_config.suspend_state = NULL;
 
-	drm_fb_helper_set_suspend_unlocked(dev->fb_helper, 0);
+	drm_client_dev_resume(dev, false);
+
 	/*
 	 * Don't enable polling if it is not initialized
 	 */
diff --git a/include/drm/drm_client.h b/include/drm/drm_client.h
index dfd5afcc9463..c03c4b0f3e94 100644
--- a/include/drm/drm_client.h
+++ b/include/drm/drm_client.h
@@ -63,6 +63,34 @@ struct drm_client_funcs {
 	 * This callback is optional.
 	 */
 	int (*hotplug)(struct drm_client_dev *client);
+
+	/**
+	 * @suspend:
+	 *
+	 * Called when suspending the device.
+	 *
+	 * This callback is optional.
+	 *
+	 * FIXME: Some callers hold the console lock when invoking this
+	 *        function. This interferes with fbdev emulation, which
+	 *        also tries to acquire the lock. Push the console lock
+	 *        into the callback and remove 'holds_console_lock'.
+	 */
+	int (*suspend)(struct drm_client_dev *client, bool holds_console_lock);
+
+	/**
+	 * @resume:
+	 *
+	 * Called when resuming the device from suspend.
+	 *
+	 * This callback is optional.
+	 *
+	 * FIXME: Some callers hold the console lock when invoking this
+	 *        function. This interferes with fbdev emulation, which
+	 *        also tries to acquire the lock. Push the console lock
+	 *        into the callback and remove 'holds_console_lock'.
+	 */
+	int (*resume)(struct drm_client_dev *client, bool holds_console_lock);
 };
 
 /**
@@ -107,6 +135,13 @@ struct drm_client_dev {
 	 */
 	struct drm_mode_set *modesets;
 
+	/**
+	 * @suspended:
+	 *
+	 * The client has been suspended.
+	 */
+	bool suspended;
+
 	/**
 	 * @hotplug_failed:
 	 *
diff --git a/include/drm/drm_client_event.h b/include/drm/drm_client_event.h
index 2c8915241120..72c97d111169 100644
--- a/include/drm/drm_client_event.h
+++ b/include/drm/drm_client_event.h
@@ -8,5 +8,7 @@ struct drm_device;
 void drm_client_dev_unregister(struct drm_device *dev);
 void drm_client_dev_hotplug(struct drm_device *dev);
 void drm_client_dev_restore(struct drm_device *dev);
+void drm_client_dev_suspend(struct drm_device *dev, bool holds_console_lock);
+void drm_client_dev_resume(struct drm_device *dev, bool holds_console_lock);
 
 #endif
-- 
2.46.0