Commit e5b8b0d4 authored by Dmitry Fleytman's avatar Dmitry Fleytman Committed by Stefan Hajnoczi
Browse files

e1000: drop check_rxov, always treat RX ring with RDH == RDT as empty 



Real HW always treats RX ring with RDH == RDT as empty.
Emulation is supposed to behave the same.

Reported-by: default avatarChris Webb <chris.webb@elastichosts.com>
Reported-by: default avatarRichard Davies <richard.davies@elastichosts.com>
Signed-off-by: default avatarDmitry Fleytman <dmitry@daynix.com>
Signed-off-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
parent 286d52eb

hw/e1000.c

+2 −5
Original line number Diff line number Diff line
@@ -92,7 +92,6 @@ typedef struct E1000State_st { 


    uint32_t rxbuf_size;

    uint32_t rxbuf_min_shift;

    int check_rxov;

    struct e1000_tx {

        unsigned char header[256];

        unsigned char vlan_header[4];
@@ -741,11 +740,11 @@ static bool e1000_has_rxbufs(E1000State *s, size_t total_size) 
    int bufs;

    /* Fast-path short packets */

    if (total_size <= s->rxbuf_size) {

        return s->mac_reg[RDH] != s->mac_reg[RDT] || !s->check_rxov;

        return s->mac_reg[RDH] != s->mac_reg[RDT];

    }

    if (s->mac_reg[RDH] < s->mac_reg[RDT]) {

        bufs = s->mac_reg[RDT] - s->mac_reg[RDH];

    } else if (s->mac_reg[RDH] > s->mac_reg[RDT] || !s->check_rxov) {

    } else if (s->mac_reg[RDH] > s->mac_reg[RDT]) {

        bufs = s->mac_reg[RDLEN] /  sizeof(struct e1000_rx_desc) +

            s->mac_reg[RDT] - s->mac_reg[RDH];

    } else {
@@ -848,7 +847,6 @@ e1000_receive(NetClientState *nc, const uint8_t *buf, size_t size) 


        if (++s->mac_reg[RDH] * sizeof(desc) >= s->mac_reg[RDLEN])

            s->mac_reg[RDH] = 0;

        s->check_rxov = 1;

        /* see comment in start_xmit; same here */

        if (s->mac_reg[RDH] == rdh_start) {

            DBGOUT(RXERR, "RDH wraparound @%x, RDT %x, RDLEN %x\n",
@@ -925,7 +923,6 @@ mac_writereg(E1000State *s, int index, uint32_t val) 
static void

set_rdt(E1000State *s, int index, uint32_t val)

{

    s->check_rxov = 0;

    s->mac_reg[index] = val & 0xffff;

    if (e1000_has_rxbufs(s, 1)) {

        qemu_flush_queued_packets(&s->nic->nc);