[PATCH 4/5] i3c: master: Negative error codes at send_ccc_cmd

[Jorge Marques]

i3c_master_send_ccc_cmd_locked would propagate cmd->err (positive,
Mx codes) to the ret variable, cascading down multiple methods until
reaching methods that explicitly stated they would return 0 on success
or negative error code. For example, the call chain:

  i3c_device_enable_ibi <- i3c_dev_enable_ibi_locked <-
  master->ops.enable_ibi <- i3c_master_enec_locked <-
  i3c_master_enec_disec_locked <- i3c_master_send_ccc_cmd_locked

Fix this by returning the ret value, callers can
still read the cmd->err value if ret is negative.

Reported-by: Dan Carpenter <dan.carpenter at linaro.org>
Closes: https://lore.kernel.org/linux-iio/aYXvT5FW0hXQwhm_@stanley.mountain/

Signed-off-by: Jorge Marques <jorge.marques at analog.com>
---
 drivers/i3c/master.c | 29 ++++++++++++-----------------
 1 file changed, 12 insertions(+), 17 deletions(-)

diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
index 3e465587c9c7..8459fffbdebb 100644
--- a/drivers/i3c/master.c
+++ b/drivers/i3c/master.c
@@ -898,11 +898,17 @@ static void i3c_ccc_cmd_init(struct i3c_ccc_cmd *cmd, bool rnw, u8 id,
 	cmd->err = I3C_ERROR_UNKNOWN;
 }
 
+/**
+ * i3c_master_send_ccc_cmd_locked() - send a CCC (Common Command Codes)
+ * @master: master used to send frames on the bus
+ * @cmd: command to send
+ *
+ * Return: 0 in case of success, or a negative error code otherwise.
+ *         I3C Mx error codes are stored in cmd->err.
+ */
 static int i3c_master_send_ccc_cmd_locked(struct i3c_master_controller *master,
 					  struct i3c_ccc_cmd *cmd)
 {
-	int ret;
-
 	if (!cmd || !master)
 		return -EINVAL;
 
@@ -920,15 +926,7 @@ static int i3c_master_send_ccc_cmd_locked(struct i3c_master_controller *master,
 	    !master->ops->supports_ccc_cmd(master, cmd))
 		return -EOPNOTSUPP;
 
-	ret = master->ops->send_ccc_cmd(master, cmd);
-	if (ret) {
-		if (cmd->err != I3C_ERROR_UNKNOWN)
-			return cmd->err;
-
-		return ret;
-	}
-
-	return 0;
+	return master->ops->send_ccc_cmd(master, cmd);
 }
 
 static struct i2c_dev_desc *
@@ -1101,8 +1099,7 @@ static int i3c_master_enec_disec_locked(struct i3c_master_controller *master,
  *
  * This function must be called with the bus lock held in write mode.
  *
- * Return: 0 in case of success, a positive I3C error code if the error is
- * one of the official Mx error codes, and a negative error code otherwise.
+ * Return: 0 in case of success, or a negative error code otherwise.
  */
 int i3c_master_disec_locked(struct i3c_master_controller *master, u8 addr,
 			    u8 evts)
@@ -1122,8 +1119,7 @@ EXPORT_SYMBOL_GPL(i3c_master_disec_locked);
  *
  * This function must be called with the bus lock held in write mode.
  *
- * Return: 0 in case of success, a positive I3C error code if the error is
- * one of the official Mx error codes, and a negative error code otherwise.
+ * Return: 0 in case of success, or a negative error code otherwise.
  */
 int i3c_master_enec_locked(struct i3c_master_controller *master, u8 addr,
 			   u8 evts)
@@ -1148,8 +1144,7 @@ EXPORT_SYMBOL_GPL(i3c_master_enec_locked);
  *
  * This function must be called with the bus lock held in write mode.
  *
- * Return: 0 in case of success, a positive I3C error code if the error is
- * one of the official Mx error codes, and a negative error code otherwise.
+ * Return: 0 in case of success, or a negative error code otherwise.
  */
 int i3c_master_defslvs_locked(struct i3c_master_controller *master)
 {

-- 
2.51.1