[PATCH 02/10] drm/client: Add hotplug_failed flag

Thomas Zimmermann
2023-01-23T10:06:11Z

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>
---
drivers/gpu/drm/drm_client.c | 5 +++++
drivers/gpu/drm/drm_fbdev_generic.c | 4 ----
include/drm/drm_client.h | 8 ++++++++
3 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
index 09ac191c202d..009e7b10455c 100644
--- 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 3d455a2e3fb5..135d58b8007b 100644
--- 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 4fc8018eddda..39482527a775 100644
--- 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,
--
2.39.0