[PATCH v2 3/8] drm/bridge/synopsys: dsi: defer probing if panel not available in bridge-attach

Heiko Stuebner
2018-06-18T10:28:01Z

When the panel-driver is build as a module it currently fails hard as the
panel cannot be probed directly:

dw_mipi_dsi_bind()
__dw_mipi_dsi_probe()
creates dsi bus
creates panel device
triggers panel module load
panel not probed (module not loaded or panel probe slow)
drm_bridge_attach
fails with -EINVAL due to empty panel_bridge

So emit a -EPROBE_DEFER in that case to give the driver another
chance at getting the display later.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
---
drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
index bb4aeca5c0f9..bd503f000ed5 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
@@ -835,6 +835,9 @@ static int dw_mipi_dsi_bridge_attach(struct drm_bridge *bridge)
return -ENODEV;
}

+ if (!dsi->panel_bridge)
+ return -EPROBE_DEFER;
+
/* Set the encoder type as caller does not know it */
bridge->encoder->encoder_type = DRM_MODE_ENCODER_DSI;

--
2.17.0