On Tue, Jan 08, 2019 at 12:25:34PM +0100, Andrzej Hajda wrote: > Issues with device links have nothing to do with hotplugging, they are > generic - lifetime of the objects (drm_bridge, drm_panel) is just > slightly different of lifetime of device links, and this is racy even if > you do not want hotplugging. Moreover since drm_dev is not device (has > no associated struct device) assuming we can reuse its parent to create > device link results in circular dependencies. How about having the device links created depending on whether the main drm driver wants them or not - that would mean that Exynos could continue avoiding them, but others that want them can have the links? I don't think the links should be created when the bridge is attached, they should be created when the main drm driver gains its first reference to the drm_bridge (via of_drm_find_bridge()) - since that's the point where things may explode if the drm_bridge goes away. Calling drm_bridge_attach() for a bridge that has been unbound will be a use-after-free bug, so using device links at that point is way too late. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
