drm/ast: Automatically clean up poll helper

Automatically clean up the conncetor-poll thread as part of the DRM
device release. The new helper drmm_kms_helper_poll_init() provides
a shared implementation for all drivers.

v6:
- fix kernel doc comment (Sui, kernel test robot)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Acked-by: Sui Jingfeng <sui.jingfeng@linux.dev>
Link: https://patchwork.freedesktop.org/patch/msgid/20240325200855.21150-14-tzimmermann@suse.de

drivers/gpu/drm/ast/ast_mode.c

@@ -1905,7 +1905,9 @@ int ast_mode_config_init(struct ast_device *ast)
 
 	drm_mode_config_reset(dev);
 
-	drm_kms_helper_poll_init(dev);
+	ret = drmm_kms_helper_poll_init(dev);
+	if (ret)
+		return ret;
 
 	return 0;
 }

drivers/gpu/drm/drm_probe_helper.c

@@ -37,6 +37,7 @@
 #include <drm/drm_crtc.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_fourcc.h>
+#include <drm/drm_managed.h>
 #include <drm/drm_modeset_helper_vtables.h>
 #include <drm/drm_print.h>
 #include <drm/drm_probe_helper.h>
@@ -951,6 +952,32 @@ void drm_kms_helper_poll_fini(struct drm_device *dev)
 }
 EXPORT_SYMBOL(drm_kms_helper_poll_fini);
 
+static void drm_kms_helper_poll_init_release(struct drm_device *dev, void *res)
+{
+	drm_kms_helper_poll_fini(dev);
+}
+
+/**
+ * drmm_kms_helper_poll_init - initialize and enable output polling
+ * @dev: drm_device
+ *
+ * This function initializes and then also enables output polling support for
+ * @dev similar to drm_kms_helper_poll_init(). Polling will automatically be
+ * cleaned up when the DRM device goes away.
+ *
+ * See drm_kms_helper_poll_init() for more information.
+ *
+ * Returns:
+ * 0 on success, or a negative errno code otherwise.
+ */
+int drmm_kms_helper_poll_init(struct drm_device *dev)
+{
+	drm_kms_helper_poll_init(dev);
+
+	return drmm_add_action_or_reset(dev, drm_kms_helper_poll_init_release, dev);
+}
+EXPORT_SYMBOL(drmm_kms_helper_poll_init);
+
 static bool check_connector_changed(struct drm_connector *connector)
 {
 	struct drm_device *dev = connector->dev;

include/drm/drm_probe_helper.h

@@ -16,6 +16,8 @@ int drm_helper_probe_single_connector_modes(struct drm_connector
 int drm_helper_probe_detect(struct drm_connector *connector,
 			    struct drm_modeset_acquire_ctx *ctx,
 			    bool force);
+
+int drmm_kms_helper_poll_init(struct drm_device *dev);
 void drm_kms_helper_poll_init(struct drm_device *dev);
 void drm_kms_helper_poll_fini(struct drm_device *dev);
 bool drm_helper_hpd_irq_event(struct drm_device *dev);