[PATCH] accel/rocket: clear rdev on device init failure

[Guangshuo Li <lgs201920130244@gmail.com>]

rocket_probe() stores the return value from rocket_device_init() in the
file-scoped rdev pointer before checking whether it is an error pointer.
If rocket_device_init() fails, rdev is left as an ERR_PTR.

The rdev pointer is also used as the marker for whether the shared rocket
device has already been initialized. A later core probe can therefore see
a non-NULL rdev, skip rocket_device_init(), and dereference the error
pointer when reading rdev->num_cores.

Save the error code and clear rdev before returning from the
rocket_device_init() failure path.

Fixes: ed98261b4168 ("accel/rocket: Add a new driver for Rockchip's NPU")
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
---
 drivers/accel/rocket/rocket_drv.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/accel/rocket/rocket_drv.c b/drivers/accel/rocket/rocket_drv.c
index 8bbbce594883..67e7f543fe4c 100644
--- a/drivers/accel/rocket/rocket_drv.c
+++ b/drivers/accel/rocket/rocket_drv.c
@@ -165,8 +165,11 @@ static int rocket_probe(struct platform_device *pdev)
 		/* First core probing, initialize DRM device. */
 		rdev = rocket_device_init(drm_dev, &rocket_drm_driver);
 		if (IS_ERR(rdev)) {
+			int err = PTR_ERR(rdev);
+
 			dev_err(&pdev->dev, "failed to initialize rocket device\n");
-			return PTR_ERR(rdev);
+			rdev = NULL;
+			return err;
 		}
 	}
 
-- 
2.43.0