Currently there is no way for a master drm driver to protect against an attached panel driver from being unloaded while it is in use. The least we can do is to indicate the usage by incrementing the module reference count. Signed-off-by: Jyri Sarha <jsarha@xxxxxx> cc: eric@xxxxxxxxxx cc: laurent.pinchart@xxxxxxxxxxxxxxxx --- I do not see any module_get/put code in drm core. Is there is a reason for that? There is two more alternative places for adding the module_get/put code. One is puting it directly to drm_panel_attach() and drm_panel_detach(). However, if the same module implements both the master drm driver and the panel (like tilcdc does with its tilcdc_panel.c), then attaching the panel will lock the module in for no good reason. Still, this solution should work with drm bridges as I do not see any reason why anybody would implement bridge drivers in the same module with the master drm driver. The other place to put the code would in the master drm driver. But for handling the situation with bridges would need the device pointer in struct drm_bridge. drivers/gpu/drm/bridge/panel.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/gpu/drm/bridge/panel.c b/drivers/gpu/drm/bridge/panel.c index 6d99d4a..0a10be6 100644 --- a/drivers/gpu/drm/bridge/panel.c +++ b/drivers/gpu/drm/bridge/panel.c @@ -161,6 +161,10 @@ struct drm_bridge *drm_panel_bridge_add(struct drm_panel *panel, if (!panel) return ERR_PTR(-EINVAL); + if (WARN_ON(!panel->dev->driver) || + !try_module_get(panel->dev->driver->owner)) + return ERR_PTR(-ENODEV); + panel_bridge = devm_kzalloc(panel->dev, sizeof(*panel_bridge), GFP_KERNEL); if (!panel_bridge) @@ -199,6 +203,9 @@ void drm_panel_bridge_remove(struct drm_bridge *bridge) panel_bridge = drm_bridge_to_panel_bridge(bridge); drm_bridge_remove(bridge); + + module_put(panel_bridge->panel->dev->driver->owner); + devm_kfree(panel_bridge->panel->dev, bridge); } EXPORT_SYMBOL(drm_panel_bridge_remove); -- 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
