[PATCH 4.12 189/196] drm/imx: parallel-display: Accept drm_of_find_panel_or_bridge failure

[Greg Kroah-Hartman]

4.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>

commit 799ee2970485dc206c3bf347d6e6827c04d5e4f9 upstream.

The parallel panel driver should continue to work without having an
endpoint linking to an panel in DT for backwards compatibility.
With the recent switch to drm_of_find_panel_or_bridge, an absent
panel results in a failure with -ENODEV error return code. To restore
the old behaviour, ignore the -ENODEV return code.

Reported-by: Nikita Yushchenko <nikita.yoush@xxxxxxxxxxxxxxxxxx>
Fixes: ebc944613567 ("drm: convert drivers to use drm_of_find_panel_or_bridge")
Tested-by: Chris Healy <cphealy@xxxxxxxxx>
Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/gpu/drm/imx/parallel-display.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpu/drm/imx/parallel-display.c
+++ b/drivers/gpu/drm/imx/parallel-display.c
@@ -237,7 +237,7 @@ static int imx_pd_bind(struct device *de
 
 	/* port@1 is the output port */
 	ret = drm_of_find_panel_or_bridge(np, 1, 0, &imxpd->panel, &imxpd->bridge);
-	if (ret)
+	if (ret && ret != -ENODEV)
 		return ret;
 
 	imxpd->dev = dev;