drm/omap: dsi: Ensure the device is active during probe

The probe function performs hardware access to read the number of
supported data lanes from a configuration register and thus requires the
device to be active. Ensure this by surrounding the access with
dsi_runtime_get() and dsi_runtime_put() calls.

Fixes: edb715df ("drm/omap: dss: dsi: Move initialization code from bind to probe")
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181110111654.4387-4-laurent.pinchart@ideasonboard.com

drivers/gpu/drm/omapdrm/dss/dsi.c

@@ -5409,11 +5409,14 @@ static int dsi_probe(struct platform_device *pdev)
 
 	/* DSI on OMAP3 doesn't have register DSI_GNQ, set number
 	 * of data to 3 by default */
-	if (dsi->data->quirks & DSI_QUIRK_GNQ)
+	if (dsi->data->quirks & DSI_QUIRK_GNQ) {
+		dsi_runtime_get(dsi);
 		/* NB_DATA_LANES */
 		dsi->num_lanes_supported = 1 + REG_GET(dsi, DSI_GNQ, 11, 9);
-	else
+		dsi_runtime_put(dsi);
+	} else {
 		dsi->num_lanes_supported = 3;
+	}
 
 	r = dsi_init_output(dsi);
 	if (r)