diff options
Diffstat (limited to 'usrp2/firmware/lib/ethernet.c')
| -rw-r--r-- | usrp2/firmware/lib/ethernet.c | 63 |
1 files changed, 61 insertions, 2 deletions
diff --git a/usrp2/firmware/lib/ethernet.c b/usrp2/firmware/lib/ethernet.c index 0e2f46167..d19287044 100644 --- a/usrp2/firmware/lib/ethernet.c +++ b/usrp2/firmware/lib/ethernet.c @@ -86,6 +86,36 @@ ed_link_speed_change(int speed) ed_link_up(speed); } +static void +print_flow_control(int flow_control) +{ + static const char *flow_control_msg[4] = { + "NONE", "WE_TX", "WE_RX", "SYMMETRIC" + }; + putstr("ethernet flow control: "); + puts(flow_control_msg[flow_control & 0x3]); +} + +static void +check_flow_control_resolution(void) +{ + static const unsigned char table[16] = { + // index = {local_asm, local_pause, partner_asm, partner_pause} + FC_NONE, FC_NONE, FC_NONE, FC_NONE, + FC_NONE, FC_SYMM, FC_NONE, FC_SYMM, + FC_NONE, FC_NONE, FC_NONE, FC_WE_TX, + FC_NONE, FC_SYMM, FC_WE_RX, FC_SYMM + }; + + int us = eth_mac_miim_read(PHY_AUTONEG_ADV); + int lp = eth_mac_miim_read(PHY_LP_ABILITY); + int index = (((us >> 10) & 0x3) << 2) | ((lp >> 10) & 0x3); + ed_state.flow_control = table[index]; + + if (1) + print_flow_control(ed_state.flow_control); +} + /* * Read the PHY state register to determine link state and speed */ @@ -123,6 +153,8 @@ ed_check_phy_state(void) new_speed = S_UNKNOWN; break; } + + check_flow_control_resolution(); } else { // link's down if (VERBOSE) @@ -194,9 +226,36 @@ ethernet_init(void) pic_register_handler(IRQ_PHY, eth_phy_irq_handler); - // Advertise that we handle PAUSE frames and asymmetric pause direction. + // Advertise our flow control configuation. + // + // We and the link partner each specify two bits in the base page + // related to autoconfiguration: NWAY_AR_PAUSE and NWAY_AR_ASM_DIR. + // The bits say what a device is "willing" to do, not what may actually + // happen as a result of the negotiation. There are 4 cases: + // + // PAUSE ASM_DIR + // + // 0 0 I have no flow control capability. + // + // 1 0 I both assert and respond to flow control. + // + // 0 1 I assert flow control, but cannot respond. That is, + // I want to be able to send PAUSE frames, but will ignore any + // you send to me. (This is our configuration.) + // + // 1 1 I can both assert and respond to flow control AND I am willing + // to operate symmetrically OR asymmetrically in EITHER direction. + // (We hope the link partner advertises this, otherwise we don't + // get what we want.) + int t = eth_mac_miim_read(PHY_AUTONEG_ADV); - eth_mac_miim_write(PHY_AUTONEG_ADV, t | NWAY_AR_PAUSE | NWAY_AR_ASM_DIR); + t &= ~(NWAY_AR_PAUSE | NWAY_AR_ASM_DIR); + t |= NWAY_AR_ASM_DIR; + + // Say we can't to 10BASE-T or 100BASE-TX, half or full duplex + t &= ~(NWAY_AR_10T_HD_CAPS | NWAY_AR_10T_FD_CAPS | NWAY_AR_100TX_HD_CAPS | NWAY_AR_100TX_FD_CAPS); + + eth_mac_miim_write(PHY_AUTONEG_ADV, t); // Restart autonegotation. // We want to ensure that we're advertising our PAUSE capabilities. |