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authoraliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162>2009-03-20 16:18:39 +0000
committeraliguori <aliguori@c046a42c-6fe2-441c-8c8c-71466251a162>2009-03-20 16:18:39 +0000
commite58843d0f117b2a30d27552b509d7cf24a0c4ba6 (patch)
treeaf1acaed1ccf16daeeea20b276ce48e135bf2126
parent0e39d3f89b796dc3bc80409309c738a01d8c20d2 (diff)
downloadqemu-e58843d0f117b2a30d27552b509d7cf24a0c4ba6.tar.gz
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 <alex.williamson@hp.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/branches/stable_0_10_0@6867 c046a42c-6fe2-441c-8c8c-71466251a162
-rw-r--r--hw/e1000.c4
1 files 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);