----- Original Message -----
> Some drivers set RDT=RDH. Oddly, this works on real hardware. To work
> around this, autodecrement RDT when this happens.
>
> Signed-off-by: Richard Tollerton <rich.toller...@ni.com>
> Signed-off-by: Jeff Westfahl <jeff.westf...@ni.com>
> ---
> hw/net/e1000.c | 6 ++++++
> 1 file changed, 6 insertions(+)
Please describe more details on the issue.
The spec 3.2.6 said:
"
When the head pointer is equal to the tail pointer, the ring is empty.
"
So RDT=RDH in fact empty the ring. No?
>
> diff --git a/hw/net/e1000.c b/hw/net/e1000.c
> index 44ae3a8..b8cbfc1 100644
> --- a/hw/net/e1000.c
> +++ b/hw/net/e1000.c
> @@ -1152,6 +1152,12 @@ mac_writereg(E1000State *s, int index, uint32_t val)
> static void
> set_rdt(E1000State *s, int index, uint32_t val)
> {
> + if (val == s->mac_reg[RDH]) { /* Decrement RDT if it's too big */
> + if (val == 0) {
> + val = s->mac_reg[RDLEN] / sizeof(struct e1000_rx_desc);
> + }
> + val--;
> + }
> s->mac_reg[index] = val & 0xffff;
> if (e1000_has_rxbufs(s, 1)) {
> qemu_flush_queued_packets(qemu_get_queue(s->nic));
> --
> 2.1.3
>
>
>
