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@nxp.com --- 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);