Index: share/man/man4/em.4 =================================================================== --- share/man/man4/em.4 +++ share/man/man4/em.4 @@ -31,7 +31,7 @@ .\" .\" $FreeBSD$ .\" -.Dd October 11, 2011 +.Dd August 05, 2015 .Dt EM 4 .Os .Sh NAME @@ -205,6 +205,11 @@ prompt before booting the kernel or stored in .Xr loader.conf 5 . .Bl -tag -width indent +.It Va hw.em.disable_crc_stripping +Disable or enable hardware stripping of CRC field. +This is mostly useful on BMC/IPMI shared interfaces where stripping the CRC +causes remote access over IPMI to fail. +Default 0 (enabled) .It Va hw.em.eee_setting Disable or enable Energy Efficient Ethernet. Default 1 (disabled). Index: sys/dev/e1000/if_em.c =================================================================== --- sys/dev/e1000/if_em.c +++ sys/dev/e1000/if_em.c @@ -366,6 +366,10 @@ static SYSCTL_NODE(_hw, OID_AUTO, em, CTLFLAG_RD, 0, "EM driver parameters"); +static int em_disable_crc_stripping = 0; +SYSCTL_INT(_hw_em, OID_AUTO, disable_crc_stripping, CTLFLAG_RD, + &em_disable_crc_stripping, 0, "Disable CRC Stripping"); + static int em_tx_int_delay_dflt = EM_TICKS_TO_USECS(EM_TIDV); static int em_rx_int_delay_dflt = EM_TICKS_TO_USECS(EM_RDTR); SYSCTL_INT(_hw_em, OID_AUTO, tx_int_delay, CTLFLAG_RDTUN, &em_tx_int_delay_dflt, @@ -4514,7 +4518,8 @@ (hw->mac.mc_filter_type << E1000_RCTL_MO_SHIFT); /* Strip the CRC */ - rctl |= E1000_RCTL_SECRC; + if (!em_disable_crc_stripping) + rctl |= E1000_RCTL_SECRC; /* Make sure VLAN Filters are off */ rctl &= ~E1000_RCTL_VFE;