From: Mika Westerberg Date: Tue, 30 Aug 2022 15:32:46 +0000 (+0300) Subject: net: thunderbolt: Enable DMA paths only after rings are enabled X-Git-Tag: v6.6.17~6504^2~300^2~4 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=ff7cd07f306406493f7b78890475e85b6d0811ed;p=platform%2Fkernel%2Flinux-rpi.git net: thunderbolt: Enable DMA paths only after rings are enabled If the other host starts sending packets early on it is possible that we are still in the middle of populating the initial Rx ring packets to the ring. This causes the tbnet_poll() to mess over the queue and causes list corruption. This happens specifically when connected with macOS as it seems start sending various IP discovery packets as soon as its side of the paths are configured. To prevent this we move the DMA path enabling to happen after we have primed the Rx ring. This makes sure no incoming packets can arrive before we are ready to handle them. Fixes: e69b6c02b4c3 ("net: Add support for networking over Thunderbolt cable") Cc: stable@vger.kernel.org Signed-off-by: Mika Westerberg Signed-off-by: David S. Miller --- diff --git a/drivers/net/thunderbolt.c b/drivers/net/thunderbolt.c index ff5d0e9..ab3f0456 100644 --- a/drivers/net/thunderbolt.c +++ b/drivers/net/thunderbolt.c @@ -612,18 +612,13 @@ static void tbnet_connected_work(struct work_struct *work) return; } - /* Both logins successful so enable the high-speed DMA paths and - * start the network device queue. + /* Both logins successful so enable the rings, high-speed DMA + * paths and start the network device queue. + * + * Note we enable the DMA paths last to make sure we have primed + * the Rx ring before any incoming packets are allowed to + * arrive. */ - ret = tb_xdomain_enable_paths(net->xd, net->local_transmit_path, - net->rx_ring.ring->hop, - net->remote_transmit_path, - net->tx_ring.ring->hop); - if (ret) { - netdev_err(net->dev, "failed to enable DMA paths\n"); - return; - } - tb_ring_start(net->tx_ring.ring); tb_ring_start(net->rx_ring.ring); @@ -635,10 +630,21 @@ static void tbnet_connected_work(struct work_struct *work) if (ret) goto err_free_rx_buffers; + ret = tb_xdomain_enable_paths(net->xd, net->local_transmit_path, + net->rx_ring.ring->hop, + net->remote_transmit_path, + net->tx_ring.ring->hop); + if (ret) { + netdev_err(net->dev, "failed to enable DMA paths\n"); + goto err_free_tx_buffers; + } + netif_carrier_on(net->dev); netif_start_queue(net->dev); return; +err_free_tx_buffers: + tbnet_free_buffers(&net->tx_ring); err_free_rx_buffers: tbnet_free_buffers(&net->rx_ring); err_stop_rings: