From d6a77ba0eb92d8ffa4b05a442fc20d0a9b11c4c4 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Thu, 27 Sep 2018 14:41:30 +0200 Subject: Revert "drm/panel: Add device_link from panel device to DRM device" This reverts commit 0c08754b59da5557532d946599854e6df28edc22. commit 0c08754b59da ("drm/panel: Add device_link from panel device to DRM device") creates a circular dependency under these circumstances: 1. The panel depends on dsi-host because it is MIPI-DSI child device. 2. dsi-host depends on the drm parent device (connector->dev->dev) this should be allowed. 3. drm parent dev (connector->dev->dev) depends on the panel after this patch. This makes the dependency circular and while it appears it does not affect any in-tree drivers (they do not seem to have dsi hosts depending on the same parent device) this does not seem right. As noted in a response from Andrzej Hajda, the intent is likely to make the panel dependent on the DRM device (connector->dev) not its parent. But we have no way of doing that since the DRM device doesn't contain any struct device on its own (arguably it should). Revert this until a proper approach is figured out. Cc: Jyri Sarha Cc: Eric Anholt Cc: Andrzej Hajda Signed-off-by: Linus Walleij Signed-off-by: Sean Paul Link: https://patchwork.freedesktop.org/patch/msgid/20180927124130.9102-1-linus.walleij@linaro.org --- drivers/gpu/drm/drm_panel.c | 10 ---------- include/drm/drm_panel.h | 1 - 2 files changed, 11 deletions(-) diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c index b902361dee6e..1d9a9d2fe0e0 100644 --- a/drivers/gpu/drm/drm_panel.c +++ b/drivers/gpu/drm/drm_panel.c @@ -24,7 +24,6 @@ #include #include -#include #include #include @@ -105,13 +104,6 @@ int drm_panel_attach(struct drm_panel *panel, struct drm_connector *connector) if (panel->connector) return -EBUSY; - panel->link = device_link_add(connector->dev->dev, panel->dev, 0); - if (!panel->link) { - dev_err(panel->dev, "failed to link panel to %s\n", - dev_name(connector->dev->dev)); - return -EINVAL; - } - panel->connector = connector; panel->drm = connector->dev; @@ -133,8 +125,6 @@ EXPORT_SYMBOL(drm_panel_attach); */ int drm_panel_detach(struct drm_panel *panel) { - device_link_del(panel->link); - panel->connector = NULL; panel->drm = NULL; diff --git a/include/drm/drm_panel.h b/include/drm/drm_panel.h index 582a0ec0aa70..777814755fa6 100644 --- a/include/drm/drm_panel.h +++ b/include/drm/drm_panel.h @@ -89,7 +89,6 @@ struct drm_panel { struct drm_device *drm; struct drm_connector *connector; struct device *dev; - struct device_link *link; const struct drm_panel_funcs *funcs; -- cgit v1.2.3