[PATCH v2] media: atomisp: Fix error handling in probe

[Evgeny Novikov <novikov@ispras.ru>]

There were several issues with handling errors in lm3554_probe():
- Probe did not set the error code when v4l2_ctrl_handler_init() failed.
- It intermixed gotos for handling errors of v4l2_ctrl_handler_init()
  and media_entity_pads_init().
- It did not set the error code for failures of v4l2_ctrl_new_custom().
- Probe did not free resources in case of failures of
  atomisp_register_i2c_module().

The patch fixes all these issues.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Evgeny Novikov <novikov@ispras.ru>
---
v2: Fix suggestions from Dan Carpenter:
    - Rename labels for handling errors to clarify their meaning.
    - Set the error code for failures of v4l2_ctrl_new_custom().
---
 .../media/atomisp/i2c/atomisp-lm3554.c        | 37 ++++++++++++-------
 1 file changed, 24 insertions(+), 13 deletions(-)

diff --git a/drivers/staging/media/atomisp/i2c/atomisp-lm3554.c b/drivers/staging/media/atomisp/i2c/atomisp-lm3554.c
index 362ed44b4eff..e046489cd253 100644
--- a/drivers/staging/media/atomisp/i2c/atomisp-lm3554.c
+++ b/drivers/staging/media/atomisp/i2c/atomisp-lm3554.c
@@ -835,7 +835,6 @@ static int lm3554_probe(struct i2c_client *client)
 	int err = 0;
 	struct lm3554 *flash;
 	unsigned int i;
-	int ret;
 
 	flash = kzalloc(sizeof(*flash), GFP_KERNEL);
 	if (!flash)
@@ -844,7 +843,7 @@ static int lm3554_probe(struct i2c_client *client)
 	flash->pdata = lm3554_platform_data_func(client);
 	if (IS_ERR(flash->pdata)) {
 		err = PTR_ERR(flash->pdata);
-		goto fail1;
+		goto free_flash;
 	}
 
 	v4l2_i2c_subdev_init(&flash->sd, client, &lm3554_ops);
@@ -852,12 +851,12 @@ static int lm3554_probe(struct i2c_client *client)
 	flash->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
 	flash->mode = ATOMISP_FLASH_MODE_OFF;
 	flash->timeout = LM3554_MAX_TIMEOUT / LM3554_TIMEOUT_STEPSIZE - 1;
-	ret =
+	err =
 	    v4l2_ctrl_handler_init(&flash->ctrl_handler,
 				   ARRAY_SIZE(lm3554_controls));
-	if (ret) {
+	if (err) {
 		dev_err(&client->dev, "error initialize a ctrl_handler.\n");
-		goto fail3;
+		goto unregister_subdev;
 	}
 
 	for (i = 0; i < ARRAY_SIZE(lm3554_controls); i++)
@@ -866,14 +865,15 @@ static int lm3554_probe(struct i2c_client *client)
 
 	if (flash->ctrl_handler.error) {
 		dev_err(&client->dev, "ctrl_handler error.\n");
-		goto fail3;
+		err = flash->ctrl_handler.error;
+		goto free_handler;
 	}
 
 	flash->sd.ctrl_handler = &flash->ctrl_handler;
 	err = media_entity_pads_init(&flash->sd.entity, 0, NULL);
 	if (err) {
 		dev_err(&client->dev, "error initialize a media entity.\n");
-		goto fail2;
+		goto free_handler;
 	}
 
 	flash->sd.entity.function = MEDIA_ENT_F_FLASH;
@@ -884,16 +884,27 @@ static int lm3554_probe(struct i2c_client *client)
 
 	err = lm3554_gpio_init(client);
 	if (err) {
-		dev_err(&client->dev, "gpio request/direction_output fail");
-		goto fail3;
+		dev_err(&client->dev, "gpio request/direction_output fail.\n");
+		goto cleanup_media;
+	}
+
+	err = atomisp_register_i2c_module(&flash->sd, NULL, LED_FLASH);
+	if (err) {
+		dev_err(&client->dev, "fail to register atomisp i2c module.\n");
+		goto uninit_gpio;
 	}
-	return atomisp_register_i2c_module(&flash->sd, NULL, LED_FLASH);
-fail3:
+
+	return 0;
+
+uninit_gpio:
+	lm3554_gpio_uninit(client);
+cleanup_media:
 	media_entity_cleanup(&flash->sd.entity);
+free_handler:
 	v4l2_ctrl_handler_free(&flash->ctrl_handler);
-fail2:
+unregister_subdev:
 	v4l2_device_unregister_subdev(&flash->sd);
-fail1:
+free_flash:
 	kfree(flash);
 
 	return err;
-- 
2.26.2