[PATCH] soc: amlogic: canvas: Fix meson_canvas_get when probe failed

[Neil Armstrong]

When probe fails, a platforn_device is still associated to the node,
but dev_get_drvdata() returns NULL.

Handle this case by returning a consistent error.

Fixes: d4983983d987 ("soc: amlogic: add meson-canvas driver")
Signed-off-by: Neil Armstrong <narmstr...@baylibre.com>
---
 drivers/soc/amlogic/meson-canvas.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

This fix depends on "soc: amlogic: add missing of_node_put()" at [1]

[1] https://patchwork.kernel.org/patch/10794545/

diff --git a/drivers/soc/amlogic/meson-canvas.c 
b/drivers/soc/amlogic/meson-canvas.c
index 87a6c6e23591..151aa84bc593 100644
--- a/drivers/soc/amlogic/meson-canvas.c
+++ b/drivers/soc/amlogic/meson-canvas.c
@@ -51,6 +51,7 @@ struct meson_canvas *meson_canvas_get(struct device *dev)
 {
        struct device_node *canvas_node;
        struct platform_device *canvas_pdev;
+       struct meson_canvas *canvas;
 
        canvas_node = of_parse_phandle(dev->of_node, "amlogic,canvas", 0);
        if (!canvas_node)
@@ -63,7 +64,17 @@ struct meson_canvas *meson_canvas_get(struct device *dev)
        }
 
        of_node_put(canvas_node);
-       return dev_get_drvdata(&canvas_pdev->dev);
+
+       /*
+        * If priv is NULL, it's probably because the canvas hasn't
+        * properly initialized. Bait out with -EINVAL because, in the
+        * current state, this driver probe cannot return -EPROBE_DEFER
+        */
+       canvas = dev_get_drvdata(&canvas_pdev->dev);
+       if (!canvas)
+               return ERR_PTR(-EINVAL);
+
+       return canvas;
 }
 EXPORT_SYMBOL_GPL(meson_canvas_get);
 
-- 
2.20.1