RDMA/bnxt_re: Fix missing error handling for tx_queue

bnxt_re_fill_gen0_ext0() did not return an error when
attempting to modify CMDQ_MODIFY_ROCE_CC_MODIFY_MASK_TX_QUEUE,
leading to silent failures.

Fixed this by returning -EOPNOTSUPP for tx_queue modifications and
ensuring proper error propagation in bnxt_re_configure_cc().

Fixes: 656dff5 ("RDMA/bnxt_re: Congestion control settings using debugfs hook")
Signed-off-by: Gautam R A <[email protected]>
Link: https://patch.msgid.link/[email protected]
Reviewed-by: Kalesh AP <[email protected]>
Signed-off-by: Leon Romanovsky <[email protected]>

Author: Gautam R A

drivers/infiniband/hw/bnxt_re/debugfs.c

@@ -206,7 +206,7 @@ static ssize_t bnxt_re_cc_config_get(struct file *filp, char __user *buffer,
 	return simple_read_from_buffer(buffer, usr_buf_len, ppos, (u8 *)(buf), rc);
 }
 
-static void bnxt_re_fill_gen0_ext0(struct bnxt_qplib_cc_param *ccparam, u32 offset, u32 val)
+static int bnxt_re_fill_gen0_ext0(struct bnxt_qplib_cc_param *ccparam, u32 offset, u32 val)
 {
 	u32 modify_mask;
 
@@ -250,7 +250,7 @@ static void bnxt_re_fill_gen0_ext0(struct bnxt_qplib_cc_param *ccparam, u32 offs
 		ccparam->tcp_cp = val;
 		break;
 	case CMDQ_MODIFY_ROCE_CC_MODIFY_MASK_TX_QUEUE:
-		break;
+		return -EOPNOTSUPP;
 	case CMDQ_MODIFY_ROCE_CC_MODIFY_MASK_INACTIVITY_CP:
 		ccparam->inact_th = val;
 		break;
@@ -263,18 +263,21 @@ static void bnxt_re_fill_gen0_ext0(struct bnxt_qplib_cc_param *ccparam, u32 offs
 	}
 
 	ccparam->mask = modify_mask;
+	return 0;
 }
 
 static int bnxt_re_configure_cc(struct bnxt_re_dev *rdev, u32 gen_ext, u32 offset, u32 val)
 {
 	struct bnxt_qplib_cc_param ccparam = { };
+	int rc;
 
-	/* Supporting only Gen 0 now */
-	if (gen_ext == CC_CONFIG_GEN0_EXT0)
-		bnxt_re_fill_gen0_ext0(&ccparam, offset, val);
-	else
+	if (gen_ext != CC_CONFIG_GEN0_EXT0)
 		return -EINVAL;
 
+	rc = bnxt_re_fill_gen0_ext0(&ccparam, offset, val);
+	if (rc)
+		return rc;
+
 	bnxt_qplib_modify_cc(&rdev->qplib_res, &ccparam);
 	return 0;
 }