From bf16cc8f97ff57db191eec73346ba0333ade342b Mon Sep 17 00:00:00 2001 From: aliguori Date: Fri, 20 Mar 2009 16:13:47 +0000 Subject: [PATCH] e1000: Fix RX descriptor low threshold interrupt logic (Alex Williamson) The RXDMT0 interrupt is supposed to fire when the number of free RX descriptors drops to some fraction of the total descriptors. However in practice, it seems like we're adding this interrupt cause on every RX. Fix the logic to treat (tail - head) as the number of free entries rather than the number of used entries. Signed-off-by: Alex Williamson Signed-off-by: Anthony Liguori git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6864 c046a42c-6fe2-441c-8c8c-71466251a162 --- hw/e1000.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/hw/e1000.c b/hw/e1000.c index e6155d6a69..1644201d6e 100644 --- a/hw/e1000.c +++ b/hw/e1000.c @@ -666,8 +666,8 @@ e1000_receive(void *opaque, const uint8_t *buf, int size) n = E1000_ICS_RXT0; if ((rdt = s->mac_reg[RDT]) < s->mac_reg[RDH]) rdt += s->mac_reg[RDLEN] / sizeof(desc); - if (((rdt - s->mac_reg[RDH]) * sizeof(desc)) << s->rxbuf_min_shift >= - s->mac_reg[RDLEN]) + if (((rdt - s->mac_reg[RDH]) * sizeof(desc)) <= s->mac_reg[RDLEN] >> + s->rxbuf_min_shift) n |= E1000_ICS_RXDMT0; set_ics(s, 0, n); -- 2.11.4.GIT