4.14-stable review patch. If anyone has any objections, please let me know.
------------------ From: Jakub Kicinski <[email protected]> [ Upstream commit ff58e2df62ce29d0552278c290ae494b30fe0c6f ] When FW floods the driver with control messages try to exit the cmsg processing loop every now and then to avoid soft lockups. Cmsg processing is generally very lightweight so 512 seems like a reasonable budget, which should not be exceeded under normal conditions. Fixes: 77ece8d5f196 ("nfp: add control vNIC datapath") Signed-off-by: Jakub Kicinski <[email protected]> Reviewed-by: Simon Horman <[email protected]> Tested-by: Pieter Jansen van Vuuren <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/net/ethernet/netronome/nfp/nfp_net_common.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) --- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c +++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c @@ -2058,14 +2058,17 @@ nfp_ctrl_rx_one(struct nfp_net *nn, stru return true; } -static void nfp_ctrl_rx(struct nfp_net_r_vector *r_vec) +static bool nfp_ctrl_rx(struct nfp_net_r_vector *r_vec) { struct nfp_net_rx_ring *rx_ring = r_vec->rx_ring; struct nfp_net *nn = r_vec->nfp_net; struct nfp_net_dp *dp = &nn->dp; + unsigned int budget = 512; - while (nfp_ctrl_rx_one(nn, dp, r_vec, rx_ring)) + while (nfp_ctrl_rx_one(nn, dp, r_vec, rx_ring) && budget--) continue; + + return budget; } static void nfp_ctrl_poll(unsigned long arg) @@ -2077,9 +2080,13 @@ static void nfp_ctrl_poll(unsigned long __nfp_ctrl_tx_queued(r_vec); spin_unlock_bh(&r_vec->lock); - nfp_ctrl_rx(r_vec); - - nfp_net_irq_unmask(r_vec->nfp_net, r_vec->irq_entry); + if (nfp_ctrl_rx(r_vec)) { + nfp_net_irq_unmask(r_vec->nfp_net, r_vec->irq_entry); + } else { + tasklet_schedule(&r_vec->tasklet); + nn_dp_warn(&r_vec->nfp_net->dp, + "control message budget exceeded!\n"); + } } /* Setup and Configuration
