scsi: ufs: core: Fix the return value documentation

ufshcd_wait_for_dev_cmd() and all its callers can return an OCS error.
OCS errors are represented by positive integers. Remove the WARN_ONCE()
statements that complain about positive error codes and update the
documentation.

Keep the behavior of ufshcd_wait_for_dev_cmd() because this return value
may end be passed as the second argument of bsg_job_done() and
bsg_job_done() handles positive and negative error codes differently.

Cc: Peter Wang <[e-mail]>
Fixes: cc59f3b68542 ("scsi: ufs: core: Improve return value documentation")
Signed-off-by: Bart Van Assche <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Reviewed-by: Peter Wang <[e-mail]>
Signed-off-by: Martin K. Petersen <[e-mail]>

drivers/ufs/core/ufshcd.c

···
 }
 
 /*
- * Return: 0 upon success; < 0 upon failure.
+ * Return: 0 upon success; > 0 in case the UFS device reported an OCS error;
+ * < 0 if another error occurred.
  */
 static int ufshcd_wait_for_dev_cmd(struct ufs_hba *hba,
 		struct ufshcd_lrb *lrbp, int max_timeout)
···
 		}
 	}
 
-	WARN_ONCE(err > 0, "Incorrect return value %d > 0\n", err);
 	return err;
 }
 
···
 }
 
 /*
- * Return: 0 upon success; < 0 upon failure.
+ * Return: 0 upon success; > 0 in case the UFS device reported an OCS error;
+ * < 0 if another error occurred.
  */
 static int ufshcd_issue_dev_cmd(struct ufs_hba *hba, struct ufshcd_lrb *lrbp,
 			  const u32 tag, int timeout)
···
  * @cmd_type: specifies the type (NOP, Query...)
  * @timeout: timeout in milliseconds
  *
- * Return: 0 upon success; < 0 upon failure.
+ * Return: 0 upon success; > 0 in case the UFS device reported an OCS error;
+ * < 0 if another error occurred.
  *
  * NOTE: Since there is only one available tag for device management commands,
  * it is expected you hold the hba->dev_cmd.lock mutex.
···
 	(*request)->upiu_req.selector = selector;
 }
 
+/*
+ * Return: 0 upon success; > 0 in case the UFS device reported an OCS error;
+ * < 0 if another error occurred.
+ */
 static int ufshcd_query_flag_retry(struct ufs_hba *hba,
 	enum query_opcode opcode, enum flag_idn idn, u8 index, bool *flag_res)
 {
···
 		dev_err(hba->dev,
 			"%s: query flag, opcode %d, idn %d, failed with error %d after %d retries\n",
 			__func__, opcode, idn, ret, retries);
-	WARN_ONCE(ret > 0, "Incorrect return value %d > 0\n", ret);
 	return ret;
 }
 
···
  * @index: flag index to access
  * @flag_res: the flag value after the query request completes
  *
- * Return: 0 for success; < 0 upon failure.
+ * Return: 0 upon success; > 0 in case the UFS device reported an OCS error;
+ * < 0 if another error occurred.
  */
 int ufshcd_query_flag(struct ufs_hba *hba, enum query_opcode opcode,
 			enum flag_idn idn, u8 index, bool *flag_res)
···
 
 out_unlock:
 	ufshcd_dev_man_unlock(hba);
-	WARN_ONCE(err > 0, "Incorrect return value %d > 0\n", err);
 	return err;
 }
 
···
  * @selector: selector field
  * @attr_val: the attribute value after the query request completes
  *
- * Return: 0 upon success; < 0 upon failure.
-*/
+ * Return: 0 upon success; > 0 in case the UFS device reported an OCS error;
+ * < 0 if another error occurred.
+ */
 int ufshcd_query_attr(struct ufs_hba *hba, enum query_opcode opcode,
 		      enum attr_idn idn, u8 index, u8 selector, u32 *attr_val)
 {
···
 
 out_unlock:
 	ufshcd_dev_man_unlock(hba);
-	WARN_ONCE(err > 0, "Incorrect return value %d > 0\n", err);
 	return err;
 }
 
···
  * @attr_val: the attribute value after the query request
  * completes
  *
- * Return: 0 for success; < 0 upon failure.
-*/
+ * Return: 0 upon success; > 0 in case the UFS device reported an OCS error;
+ * < 0 if another error occurred.
+ */
 int ufshcd_query_attr_retry(struct ufs_hba *hba,
 	enum query_opcode opcode, enum attr_idn idn, u8 index, u8 selector,
 	u32 *attr_val)
···
 		dev_err(hba->dev,
 			"%s: query attribute, idn %d, failed with error %d after %d retries\n",
 			__func__, idn, ret, QUERY_REQ_RETRIES);
-	WARN_ONCE(ret > 0, "Incorrect return value %d > 0\n", ret);
 	return ret;
 }
 
 /*
- * Return: 0 if successful; < 0 upon failure.
+ * Return: 0 upon success; > 0 in case the UFS device reported an OCS error;
+ * < 0 if another error occurred.
  */
 static int __ufshcd_query_descriptor(struct ufs_hba *hba,
 			enum query_opcode opcode, enum desc_idn idn, u8 index,
···
 out_unlock:
 	hba->dev_cmd.query.descriptor = NULL;
 	ufshcd_dev_man_unlock(hba);
-	WARN_ONCE(err > 0, "Incorrect return value %d > 0\n", err);
 	return err;
 }
 
···
  * The buf_len parameter will contain, on return, the length parameter
  * received on the response.
  *
- * Return: 0 for success; < 0 upon failure.
+ * Return: 0 upon success; > 0 in case the UFS device reported an OCS error;
+ * < 0 if another error occurred.
  */
 int ufshcd_query_descriptor_retry(struct ufs_hba *hba,
 				  enum query_opcode opcode,
···
 			break;
 	}
 
-	WARN_ONCE(err > 0, "Incorrect return value %d > 0\n", err);
 	return err;
 }
 
···
  * @param_read_buf: pointer to buffer where parameter would be read
  * @param_size: sizeof(param_read_buf)
  *
- * Return: 0 in case of success; < 0 upon failure.
+ * Return: 0 upon success; > 0 in case the UFS device reported an OCS error;
+ * < 0 if another error occurred.
  */
 int ufshcd_read_desc_param(struct ufs_hba *hba,
 			   enum desc_idn desc_id,
···
 out:
 	if (is_kmalloc)
 		kfree(desc_buf);
-	WARN_ONCE(ret > 0, "Incorrect return value %d > 0\n", ret);
 	return ret;
 }
 
···
  *
  * Set fDeviceInit flag and poll until device toggles it.
  *
- * Return: 0 upon success; < 0 upon failure.
+ * Return: 0 upon success; > 0 in case the UFS device reported an OCS error;
+ * < 0 if another error occurred.
  */
 static int ufshcd_complete_dev_init(struct ufs_hba *hba)
 {
···
  * not respond with NOP IN UPIU within timeout of %NOP_OUT_TIMEOUT
  * and we retry sending NOP OUT for %NOP_OUT_RETRIES iterations.
  *
- * Return: 0 upon success; < 0 upon failure.
+ * Return: 0 upon success; > 0 in case the UFS device reported an OCS error;
+ * < 0 if another error occurred.
  */
 static int ufshcd_verify_dev_init(struct ufs_hba *hba)
 {
···
  * as the device is allowed to manage its own way of handling background
  * operations.
  *
- * Return: zero on success, non-zero on failure.
+ * Return: 0 upon success; > 0 in case the UFS device reported an OCS error;
+ * < 0 if another error occurred.
  */
 static int ufshcd_enable_auto_bkops(struct ufs_hba *hba)
 {
···
  * host is idle so that BKOPS are managed effectively without any negative
  * impacts.
  *
- * Return: zero on success, non-zero on failure.
+ * Return: 0 upon success; > 0 in case the UFS device reported an OCS error;
+ * < 0 if another error occurred.
  */
 static int ufshcd_disable_auto_bkops(struct ufs_hba *hba)
 {
···
 				__func__, err);
 }
 
+/*
+ * Return: 0 upon success; > 0 in case the UFS device reported an OCS error;
+ * < 0 if another error occurred.
+ */
 int ufshcd_read_device_lvl_exception_id(struct ufs_hba *hba, u64 *exception_id)
 {
 	struct utp_upiu_query_v4_0 *upiu_resp;
···
  * @sg_list:	Pointer to SG list when DATA IN/OUT UPIU is required in ARPMB operation
  * @dir:	DMA direction
  *
- * Return: zero on success, non-zero on failure.
+ * Return: 0 upon success; > 0 in case the UFS device reported an OCS error;
+ * < 0 if another error occurred.
  */
 int ufshcd_advanced_rpmb_req_handler(struct ufs_hba *hba, struct utp_upiu_req *req_upiu,
 			 struct utp_upiu_req *rsp_upiu, struct ufs_ehs *req_ehs,