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: Chris Webb <chris.webb@elastichosts.com>
Reported-by: Richard Davies <richard.davies@elastichosts.com>
Signed-off-by: Dmitry Fleytman <dmitry@daynix.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This commit is contained in:
Dmitry Fleytman 2012-10-19 07:56:55 +02:00 committed by Stefan Hajnoczi
parent 286d52ebfc
commit e5b8b0d4ba

View file

@ -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);