[dpdk-dev] [PATCH v2] ethdev: add comment to warn of ABI breakage

[Ciara Power <ciara.power@intel.com>]

If a function is added to the eth_dev_ops struct before
tx_descriptor_status function, this will cause ABI breakage. This is due
to static inline functions using this function, and some other functions
above it in the struct, so they cannot change position. A comment is
added to inform developers of this possible breakage.

Signed-off-by: Ciara Power <ciara.power@intel.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>
Reviewed-by: Andrew Rybchenko <arybchenko@solarflare.com>

---
V2: Added empty first line in comment
---
 lib/librte_ethdev/rte_ethdev_core.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/lib/librte_ethdev/rte_ethdev_core.h b/lib/librte_ethdev/rte_ethdev_core.h
index 7bf97e24e..9933ffdc1 100644
--- a/lib/librte_ethdev/rte_ethdev_core.h
+++ b/lib/librte_ethdev/rte_ethdev_core.h
@@ -667,6 +667,10 @@ struct eth_dev_ops {
 	/**< Check the status of a Rx descriptor. */
 	eth_tx_descriptor_status_t tx_descriptor_status;
 	/**< Check the status of a Tx descriptor. */
+	/*
+	 * Static inline functions use functions above this comment.
+	 * New dev_ops functions should be added below to avoid breaking ABI.
+	 */
 	eth_rx_enable_intr_t       rx_queue_intr_enable;  /**< Enable Rx queue interrupt. */
 	eth_rx_disable_intr_t      rx_queue_intr_disable; /**< Disable Rx queue interrupt. */
 	eth_tx_queue_setup_t       tx_queue_setup;/**< Set up device TX queue. */
-- 
2.17.1