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 <dave.jiang@intel.com>
Reported-by: Alex Depoutovitch <alex@pernixdata.com>
Tested-by: Alex Depoutovitch <alex@pernixdata.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
index ec4775f..4321488 100644
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -124,6 +124,7 @@
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 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 @@
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 @@
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 @@
* 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 @@
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 @@
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 @@
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 @@
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);
}