[PATCH 8/9] net/sfc: drop AUTO from FEC capabilities and fix the comment

Ivan Malov
2025-12-29T21:36:26Z

AUTO is not a capability. It is rather a special value. Do not indicate it.
Also, improve the comment to explain this change and the overall principle.

Fixes: b526903f308e ("net/sfc: offer support for 200G link ability on new adaptors")
Fixes: 5efa8fc1cfc0 ("net/sfc: support FEC feature")
Cc: stable@dpdk.org

Signed-off-by: Ivan Malov <ivan.malov@arknetworks.am>
Reviewed-by: Andy Moreton <andy.moreton@amd.com>
---
drivers/net/sfc/sfc_ethdev.c | 31 ++++++++++++++-----------------
1 file changed, 14 insertions(+), 17 deletions(-)

diff --git a/drivers/net/sfc/sfc_ethdev.c b/drivers/net/sfc/sfc_ethdev.c
index fc759f52fe..7c2abaab6b 100644
--- a/drivers/net/sfc/sfc_ethdev.c
+++ b/drivers/net/sfc/sfc_ethdev.c
@@ -2517,18 +2517,20 @@ sfc_fec_get_capa_speed_to_fec(uint32_t supported_caps,
rs = true;

/*
- * NOFEC and AUTO FEC modes are always supported.
- * FW does not provide information about the supported
- * FEC modes per the link speed.
- * Supported FEC depends on supported link speeds and
- * supported FEC modes by a device.
+ * NOFEC can always be requested, but if the link technology for the
+ * intended speed mandates FEC, doing so will not bring the link up.
+ *
+ * FW cannot report supported FEC modes per speed/link technology,
+ * so use best-effort approximation to fill in the capabilities.
+ *
+ * Do not indicate 'AUTO'. This bit is reserved for user
+ * input. It has nothing to do with capability reporting.
*/
if (supported_caps & (1u << EFX_PHY_CAP_10000FDX)) {
if (speed_fec_capa != NULL) {
speed_fec_capa[num].speed = RTE_ETH_SPEED_NUM_10G;
speed_fec_capa[num].capa =
- RTE_ETH_FEC_MODE_CAPA_MASK(NOFEC) |
- RTE_ETH_FEC_MODE_CAPA_MASK(AUTO);
+ RTE_ETH_FEC_MODE_CAPA_MASK(NOFEC);
if (baser) {
speed_fec_capa[num].capa |=
RTE_ETH_FEC_MODE_CAPA_MASK(BASER);
@@ -2540,8 +2542,7 @@ sfc_fec_get_capa_speed_to_fec(uint32_t supported_caps,
if (speed_fec_capa != NULL) {
speed_fec_capa[num].speed = RTE_ETH_SPEED_NUM_25G;
speed_fec_capa[num].capa =
- RTE_ETH_FEC_MODE_CAPA_MASK(NOFEC) |
- RTE_ETH_FEC_MODE_CAPA_MASK(AUTO);
+ RTE_ETH_FEC_MODE_CAPA_MASK(NOFEC);
if (baser) {
speed_fec_capa[num].capa |=
RTE_ETH_FEC_MODE_CAPA_MASK(BASER);
@@ -2557,8 +2558,7 @@ sfc_fec_get_capa_speed_to_fec(uint32_t supported_caps,
if (speed_fec_capa != NULL) {
speed_fec_capa[num].speed = RTE_ETH_SPEED_NUM_40G;
speed_fec_capa[num].capa =
- RTE_ETH_FEC_MODE_CAPA_MASK(NOFEC) |
- RTE_ETH_FEC_MODE_CAPA_MASK(AUTO);
+ RTE_ETH_FEC_MODE_CAPA_MASK(NOFEC);
if (baser) {
speed_fec_capa[num].capa |=
RTE_ETH_FEC_MODE_CAPA_MASK(BASER);
@@ -2570,8 +2570,7 @@ sfc_fec_get_capa_speed_to_fec(uint32_t supported_caps,
if (speed_fec_capa != NULL) {
speed_fec_capa[num].speed = RTE_ETH_SPEED_NUM_50G;
speed_fec_capa[num].capa =
- RTE_ETH_FEC_MODE_CAPA_MASK(NOFEC) |
- RTE_ETH_FEC_MODE_CAPA_MASK(AUTO);
+ RTE_ETH_FEC_MODE_CAPA_MASK(NOFEC);
if (baser) {
speed_fec_capa[num].capa |=
RTE_ETH_FEC_MODE_CAPA_MASK(BASER);
@@ -2587,8 +2586,7 @@ sfc_fec_get_capa_speed_to_fec(uint32_t supported_caps,
if (speed_fec_capa != NULL) {
speed_fec_capa[num].speed = RTE_ETH_SPEED_NUM_100G;
speed_fec_capa[num].capa =
- RTE_ETH_FEC_MODE_CAPA_MASK(NOFEC) |
- RTE_ETH_FEC_MODE_CAPA_MASK(AUTO);
+ RTE_ETH_FEC_MODE_CAPA_MASK(NOFEC);
if (rs) {
speed_fec_capa[num].capa |=
RTE_ETH_FEC_MODE_CAPA_MASK(RS);
@@ -2600,8 +2598,7 @@ sfc_fec_get_capa_speed_to_fec(uint32_t supported_caps,
if (speed_fec_capa != NULL) {
speed_fec_capa[num].speed = RTE_ETH_SPEED_NUM_200G;
speed_fec_capa[num].capa =
- RTE_ETH_FEC_MODE_CAPA_MASK(NOFEC) |
- RTE_ETH_FEC_MODE_CAPA_MASK(AUTO);
+ RTE_ETH_FEC_MODE_CAPA_MASK(NOFEC);
if (rs) {
speed_fec_capa[num].capa |=
RTE_ETH_FEC_MODE_CAPA_MASK(RS);
--
2.47.3