Current enetc_set_mm() is designed to set the priv->active_offloads bit
ENETC_F_QBU for enetc_mm_link_state_update() to act on, but if the link
is already up, it modifies the ENETC_MMCSR_ME ("Merge Enable") bit
directly.
The problem is that it only *sets* ENETC_MMCSR_ME if the link is up, it
doesn't *clear* it if needed. So subsequent enetc_get_mm() calls still
see tx-enabled as true, up until a link down event, which is when
enetc_mm_link_state_update() will get called.
This is not a functional issue as far as I can assess. It has only come
up because I'd like to uphold a simple API rule in core ethtool code:
the pMAC cannot be disabled if TX is going to be enabled. Currently,
the fact that TX remains enabled for longer than expected (after the
enetc_set_mm() call that disables it) is going to violate that rule,
which is how it was caught.
Signed-off-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
---
v1->v2: none
drivers/net/ethernet/freescale/enetc/enetc_ethtool.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
index 838750a03cf6..ee1ea71fe79e 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
@@ -1041,10 +1041,13 @@ static int enetc_set_mm(struct net_device *ndev, struct ethtool_mm_cfg *cfg,
else
priv->active_offloads &= ~ENETC_F_QBU;
- /* If link is up, enable MAC Merge right away */
- if (!!(priv->active_offloads & ENETC_F_QBU) &&
- !(val & ENETC_MMCSR_LINK_FAIL))
- val |= ENETC_MMCSR_ME;
+ /* If link is up, enable/disable MAC Merge right away */
+ if (!(val & ENETC_MMCSR_LINK_FAIL)) {
+ if (!!(priv->active_offloads & ENETC_F_QBU))
+ val |= ENETC_MMCSR_ME;
+ else
+ val &= ~ENETC_MMCSR_ME;
+ }
val &= ~ENETC_MMCSR_VT_MASK;
val |= ENETC_MMCSR_VT(cfg->verify_time);
--
2.34.1
