On Wed, Mar 29, 2023 at 8:33 PM Maxime Ripard <maxime@xxxxxxxxxx> wrote: > > On Wed, Mar 29, 2023 at 06:46:08PM +0530, Jagan Teki wrote: > > Implement a DRM-managed action helper that returns the next DSI bridge > > in the chain. > > > > Unlike general bridge return helper drmm_of_get_bridge, this helper > > uses the dsi specific panel_or_bridge helper to find the next DSI > > device in the pipeline. > > > > Helper lookup a given downstream DSI device that has been added via > > child or OF-graph port or ports node. > > > > Upstream DSI looks for downstream devices using drm pointer, port and > > endpoint number. Downstream devices added via child node don't affect > > the port and endpoint number arguments. > > > > Signed-off-by: Jagan Teki <jagan@xxxxxxxxxxxxxxxxxxxx> > > If you intend to use it with the sun4i driver, then don't. The sun4i > driver is barely using drm-managed resources, so chances are all its > resources will be freed by the time this action will run. Any idea how to check all resources will be freed before this DRM-managed action helper runs? I did test the panel insertion and removal at runtime and I can see that the action helper (drmm_drm_panel_bridge_release) is triggered at removal time. Here is the log for it. # insmod panel-bananapi-s070wv20-icn6211.ko [ 11.411894] sun4i-drm display-engine: bound 1e00000.display-frontend (ops 0xc0951eb4) [ 11.420253] sun4i-drm display-engine: bound 1e60000.display-backend (ops 0xc0951620) [ 11.428128] sun4i-drm display-engine: bound 1e70000.drc (ops 0xc0951150) [ 11.435574] sun4i-drm display-engine: No panel or bridge found... RGB output disabled [ 11.443484] sun4i-drm display-engine: bound 1c0c000.lcd-controller (ops 0xc094fdb0) [ 11.451264] sun4i-drm display-engine: bound 1ca0000.dsi (ops 0xc0952f04) [ 11.462479] [drm] Initialized sun4i-drm 1.0.0 20150629 for display-engine on minor 1 [ 11.963246] Console: switching to colour frame buffer device 100x30 [ 12.046329] sun4i-drm display-engine: [drm] fb0: sun4i-drmdrmfb frame buffer device [ 12.082641] sun6i-mipi-dsi 1ca0000.dsi: Attached device s070wv20-ct16-icn62 # rmmod panel-bananapi-s070wv20-icn6211.ko [ 16.306388] Console: switching to colour dummy device 80x30 [ 16.466963] drmm_drm_panel_bridge_release: In Thanks, Jagan.