From e902133162afd6437e372d74f2d305b0b4cc16d6 Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Tue, 23 Feb 2016 09:11:36 -0700 Subject: ntb: stop tasklet from spinning forever during shutdown. We can leave tasklet spinning forever if we disable the tasklet during qp shutdown and the tasklets are still being kicked off. This hopefully should avoid that race condition. Signed-off-by: Dave Jiang Reported-by: Alex Depoutovitch Tested-by: Alex Depoutovitch Signed-off-by: Jon Mason --- drivers/ntb/ntb_transport.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-) diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c index ec4775f0ec16..4321488d2179 100644 --- a/drivers/ntb/ntb_transport.c +++ b/drivers/ntb/ntb_transport.c @@ -124,6 +124,7 @@ struct ntb_transport_qp { bool client_ready; bool link_is_up; + bool active; u8 qp_num; /* Only 64 QP's are allowed. 0-63 */ u64 qp_bit; @@ -719,6 +720,7 @@ static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw, static void ntb_qp_link_down_reset(struct ntb_transport_qp *qp) { qp->link_is_up = false; + qp->active = false; qp->tx_index = 0; qp->rx_index = 0; @@ -926,11 +928,13 @@ static void ntb_qp_link_work(struct work_struct *work) if (val & BIT(qp->qp_num)) { dev_info(&pdev->dev, "qp %d: Link Up\n", qp->qp_num); qp->link_is_up = true; + qp->active = true; if (qp->event_handler) qp->event_handler(qp->cb_data, qp->link_is_up); - tasklet_schedule(&qp->rxc_db_work); + if (qp->active) + tasklet_schedule(&qp->rxc_db_work); } else if (nt->link_is_up) schedule_delayed_work(&qp->link_work, msecs_to_jiffies(NTB_LINK_DOWN_TIMEOUT)); @@ -1411,7 +1415,8 @@ static void ntb_transport_rxc_db(unsigned long data) if (i == qp->rx_max_entry) { /* there is more work to do */ - tasklet_schedule(&qp->rxc_db_work); + if (qp->active) + tasklet_schedule(&qp->rxc_db_work); } else if (ntb_db_read(qp->ndev) & BIT_ULL(qp->qp_num)) { /* the doorbell bit is set: clear it */ ntb_db_clear(qp->ndev, BIT_ULL(qp->qp_num)); @@ -1422,7 +1427,8 @@ static void ntb_transport_rxc_db(unsigned long data) * ntb_process_rxc and clearing the doorbell bit: * there might be some more work to do. */ - tasklet_schedule(&qp->rxc_db_work); + if (qp->active) + tasklet_schedule(&qp->rxc_db_work); } } @@ -1760,6 +1766,8 @@ void ntb_transport_free_queue(struct ntb_transport_qp *qp) pdev = qp->ndev->pdev; + qp->active = false; + if (qp->tx_dma_chan) { struct dma_chan *chan = qp->tx_dma_chan; /* Putting the dma_chan to NULL will force any new traffic to be @@ -1793,7 +1801,7 @@ void ntb_transport_free_queue(struct ntb_transport_qp *qp) qp_bit = BIT_ULL(qp->qp_num); ntb_db_set_mask(qp->ndev, qp_bit); - tasklet_disable(&qp->rxc_db_work); + tasklet_kill(&qp->rxc_db_work); cancel_delayed_work_sync(&qp->link_work); @@ -1886,7 +1894,8 @@ int ntb_transport_rx_enqueue(struct ntb_transport_qp *qp, void *cb, void *data, ntb_list_add(&qp->ntb_rx_q_lock, &entry->entry, &qp->rx_pend_q); - tasklet_schedule(&qp->rxc_db_work); + if (qp->active) + tasklet_schedule(&qp->rxc_db_work); return 0; } @@ -2069,7 +2078,8 @@ static void ntb_transport_doorbell_callback(void *data, int vector) qp_num = __ffs(db_bits); qp = &nt->qp_vec[qp_num]; - tasklet_schedule(&qp->rxc_db_work); + if (qp->active) + tasklet_schedule(&qp->rxc_db_work); db_bits &= ~BIT_ULL(qp_num); } -- cgit v1.2.3