Currently the master drm driver is not protected against the attached panel driver from becoming unavailable. Adding a device_link with DL_FLAG_AUTOREMOVE flag unbinds the master drm device (the consumer) when the panel device (the supplier) becomes unavailable. Signed-off-by: Jyri Sarha <jsarha@xxxxxx> Suggested-by: Thierry Reding <thierry.reding@xxxxxxxxx> cc: eric@xxxxxxxxxx cc: laurent.pinchart@xxxxxxxxxxxxxxxx --- It still annoys me that the unbound master drm device does not probe again if the panel device becomes available again. If there is no remedy to this, may be we should consider applying the module get/put patch[1] too. Hmmm... there was an obvious reasons not to add module gets and puts to drm_panel_attach/detach(), but is there any such reasons for not to add and remove the device link there? The bridge side look more complicated as there is no public drm_bridge_detach(), and I am not sure if the drm_bridge_remove() should remove the device link. I guess it should, if the link is there. [1] https://lists.freedesktop.org/archives/dri-devel/2018-February/166350.html drivers/gpu/drm/bridge/panel.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/drivers/gpu/drm/bridge/panel.c b/drivers/gpu/drm/bridge/panel.c index 6d99d4a..d71ddd8 100644 --- a/drivers/gpu/drm/bridge/panel.c +++ b/drivers/gpu/drm/bridge/panel.c @@ -22,6 +22,7 @@ struct panel_bridge { struct drm_connector connector; struct drm_panel *panel; u32 connector_type; + struct device_link *link; /* link to master drm dev */ }; static inline struct panel_bridge * @@ -57,6 +58,22 @@ static const struct drm_connector_funcs panel_bridge_connector_funcs = { .atomic_destroy_state = drm_atomic_helper_connector_destroy_state, }; +static int panel_bridge_link_to_master(struct panel_bridge *panel_bridge) +{ + struct device *mdev = panel_bridge->bridge.dev->dev; + struct device *pdev = panel_bridge->panel->dev; + u32 flags = DL_FLAG_AUTOREMOVE; + + panel_bridge->link = device_link_add(mdev, pdev, flags); + if (!panel_bridge->link) { + dev_err(pdev, "failed to link panel %s to %s\n", + dev_name(pdev), dev_name(mdev)); + return -EINVAL; + } + + return 0; +} + static int panel_bridge_attach(struct drm_bridge *bridge) { struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge); @@ -82,6 +99,9 @@ static int panel_bridge_attach(struct drm_bridge *bridge) drm_mode_connector_attach_encoder(&panel_bridge->connector, bridge->encoder); + if (panel_bridge_link_to_master(panel_bridge)) + return -EINVAL; + ret = drm_panel_attach(panel_bridge->panel, &panel_bridge->connector); if (ret < 0) return ret; @@ -94,6 +114,8 @@ static void panel_bridge_detach(struct drm_bridge *bridge) struct panel_bridge *panel_bridge = drm_bridge_to_panel_bridge(bridge); drm_panel_detach(panel_bridge->panel); + + device_link_del(panel_bridge->link); } static void panel_bridge_pre_enable(struct drm_bridge *bridge) -- Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
