Hi Dave, On Fri, Mar 4, 2022 at 8:48 PM Dave Stevenson <dave.stevenson@xxxxxxxxxxxxxxx> wrote: > > DSI sink devices typically want the DSI host powered up and configured > before they are powered up. pre_enable is the place this would normally > happen, but they are called in reverse order from panel/connector towards > the encoder, which is the "wrong" order. > > Add a new flag pre_enable_upstream_first that any bridge can set > to swap the order of pre_enable (and post_disable) for that and the > immediately upstream bridge. > Should the immediately upstream bridge also set the > pre_enable_upstream_first flag, the bridge upstream of that will be called > before either of those which requested pre_enable_upstream_first. > > eg: > - Panel > - Bridge 1 > - Bridge 2 pre_enable_upstream_first > - Bridge 3 > - Bridge 4 pre_enable_upstream_first > - Bridge 5 pre_enable_upstream_first > - Bridge 6 > - Encoder > Would result in pre_enable's being called as Panel, Bridge 1, Bridge 3, > Bridge 2, Bridge 6, Bridge 5, Bridge 4, Encoder. Look like this is something that I've reproduced before, isn't it? https://patchwork.kernel.org/project/dri-devel/patch/20210214194102.126146-6-jagan@xxxxxxxxxxxxxxxxxxxx/ Jagan.
