Components further up in the chain might ask us for supported formats.
Without this MEDIA_BUS_FMT_FIXED is assumed which then breaks display output with mxsfb since it can't determine a proper bus format.
We handle the bus formats that correspond to the DSI formats the bridge can potentially output (see chapter 13.6 of the i.MX 8MQ reference manual) - which matches what xsfb can input.
Fixes: b776b0f00f24 ("drm: mxsfb: Use bus_format from the nearest bridge if present")
Signed-off-by: Guido Günther agx@sigxcpu.org --- drivers/gpu/drm/bridge/nwl-dsi.c | 35 ++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+)
diff --git a/drivers/gpu/drm/bridge/nwl-dsi.c b/drivers/gpu/drm/bridge/nwl-dsi.c index a251cc1f088f..27c80d36846b 100644 --- a/drivers/gpu/drm/bridge/nwl-dsi.c +++ b/drivers/gpu/drm/bridge/nwl-dsi.c @@ -1234,6 +1234,40 @@ static void nwl_dsi_bridge_detach(struct drm_bridge *bridge) drm_of_panel_bridge_remove(dsi->dev->of_node, 1, 0); }
+static u32 *nwl_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge, + struct drm_bridge_state *bridge_state, + struct drm_crtc_state *crtc_state, + struct drm_connector_state *conn_state, + u32 output_fmt, + unsigned int *num_input_fmts) +{ + u32 *input_fmts, input_fmt; + + *num_input_fmts = 0; + + switch (output_fmt) { + /* If MEDIA_BUS_FMT_FIXED is tested, return default bus format */ + case MEDIA_BUS_FMT_FIXED: + input_fmt = MEDIA_BUS_FMT_RGB888_1X24; + break; + case MEDIA_BUS_FMT_RGB888_1X24: + case MEDIA_BUS_FMT_RGB666_1X18: + case MEDIA_BUS_FMT_RGB565_1X16: + input_fmt = output_fmt; + break; + default: + return NULL; + } + + input_fmts = kcalloc(1, sizeof(*input_fmts), GFP_KERNEL); + if (!input_fmts) + return NULL; + input_fmts[0] = input_fmt; + *num_input_fmts = 1; + + return input_fmts; +} + static const struct drm_bridge_funcs nwl_dsi_bridge_funcs = { .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state, .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state, @@ -1241,6 +1275,7 @@ static const struct drm_bridge_funcs nwl_dsi_bridge_funcs = { .atomic_check = nwl_dsi_bridge_atomic_check, .atomic_enable = nwl_dsi_bridge_atomic_enable, .atomic_disable = nwl_dsi_bridge_atomic_disable, + .atomic_get_input_bus_fmts = nwl_bridge_atomic_get_input_bus_fmts, .mode_set = nwl_dsi_bridge_mode_set, .mode_valid = nwl_dsi_bridge_mode_valid, .attach = nwl_dsi_bridge_attach,