netdev: octeon_mgmt: Fix race condition freeing TX buffers.

Under heavy load the TX cleanup tasklet and xmit threads would race
and try to free too many buffers.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David Daney 2010-05-05 13:03:09 +00:00 committed by David S. Miller
parent 62538d2490
commit 4d30b8013b

View File

@ -189,12 +189,19 @@ static void octeon_mgmt_clean_tx_buffers(struct octeon_mgmt *p)
mix_orcnt.u64 = cvmx_read_csr(CVMX_MIXX_ORCNT(port));
while (mix_orcnt.s.orcnt) {
spin_lock_irqsave(&p->tx_list.lock, flags);
mix_orcnt.u64 = cvmx_read_csr(CVMX_MIXX_ORCNT(port));
if (mix_orcnt.s.orcnt == 0) {
spin_unlock_irqrestore(&p->tx_list.lock, flags);
break;
}
dma_sync_single_for_cpu(p->dev, p->tx_ring_handle,
ring_size_to_bytes(OCTEON_MGMT_TX_RING_SIZE),
DMA_BIDIRECTIONAL);
spin_lock_irqsave(&p->tx_list.lock, flags);
re.d64 = p->tx_ring[p->tx_next_clean];
p->tx_next_clean =
(p->tx_next_clean + 1) % OCTEON_MGMT_TX_RING_SIZE;