drm/client: Add hotplug_failed flag

Signal failed hotplugging with a flag in struct drm_client_dev. If set,
the client helpers will not further try to set up the fbdev display.

This used to be signalled with a combination of cleared pointers in
struct drm_fb_helper, which prevents us from initializing these pointers
early after allocation.

The change also harmonizes behavior among DRM clients. Additional DRM
clients will now handle failed hotplugging like fbdev does.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230125200415.14123-3-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
index 09ac191..009e7b1 100644 (file)
--- a/drivers/gpu/drm/drm_client.c
+++ b/drivers/gpu/drm/drm_client.c
@@ -208,8 +208,13 @@ void drm_client_dev_hotplug(struct drm_device *dev)
                if (!client->funcs || !client->funcs->hotplug)
                        continue;
 
+               if (client->hotplug_failed)
+                       continue;
+
                ret = client->funcs->hotplug(client);
                drm_dbg_kms(dev, "%s: ret=%d\n", client->name, ret);
+               if (ret)
+                       client->hotplug_failed = true;
        }
        mutex_unlock(&dev->clientlist_mutex);
 }

diff --git a/drivers/gpu/drm/drm_fbdev_generic.c b/drivers/gpu/drm/drm_fbdev_generic.c
index 3d455a2..135d58b 100644 (file)
--- a/drivers/gpu/drm/drm_fbdev_generic.c
+++ b/drivers/gpu/drm/drm_fbdev_generic.c
@@ -382,10 +382,6 @@ static int drm_fbdev_client_hotplug(struct drm_client_dev *client)
        struct drm_device *dev = client->dev;
        int ret;
 
-       /* Setup is not retried if it has failed */
-       if (!fb_helper->dev && fb_helper->funcs)
-               return 0;
-
        if (dev->fb_helper)
                return drm_fb_helper_hotplug_event(dev->fb_helper);
 

diff --git a/include/drm/drm_client.h b/include/drm/drm_client.h
index 4fc8018..3948252 100644 (file)
--- a/include/drm/drm_client.h
+++ b/include/drm/drm_client.h
@@ -106,6 +106,14 @@ struct drm_client_dev {
         * @modesets: CRTC configurations
         */
        struct drm_mode_set *modesets;
+
+       /**
+        * @hotplug failed:
+        *
+        * Set by client hotplug helpers if the hotplugging failed
+        * before. It is usually not tried again.
+        */
+       bool hotplug_failed;
 };
 
 int drm_client_init(struct drm_device *dev, struct drm_client_dev *client,