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Commit 4d30b801 authored by David Daney's avatar David Daney Committed by David S. Miller
Browse files

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: default avatarDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 62538d24

drivers/net/octeon/octeon_mgmt.c

+9 −2
Original line number Original line Diff line number Diff line
@@ -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));

	mix_orcnt.u64 = cvmx_read_csr(CVMX_MIXX_ORCNT(port));

	while (mix_orcnt.s.orcnt) {

	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,

		dma_sync_single_for_cpu(p->dev, p->tx_ring_handle,

					ring_size_to_bytes(OCTEON_MGMT_TX_RING_SIZE),

					ring_size_to_bytes(OCTEON_MGMT_TX_RING_SIZE),

					DMA_BIDIRECTIONAL);

					DMA_BIDIRECTIONAL);





		spin_lock_irqsave(&p->tx_list.lock, flags);



		re.d64 = p->tx_ring[p->tx_next_clean];

		re.d64 = p->tx_ring[p->tx_next_clean];

		p->tx_next_clean =

		p->tx_next_clean =

			(p->tx_next_clean + 1) % OCTEON_MGMT_TX_RING_SIZE;

			(p->tx_next_clean + 1) % OCTEON_MGMT_TX_RING_SIZE;