From: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>
This must not happen - otherwise we might keep flushing
forever.
Reviewed-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>
---
drivers/net/wireless/iwlwifi/pcie/trans.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/iwlwifi/pcie/trans.c b/drivers/net/wireless/iwlwifi/pcie/trans.c
index 0f20e73..4845d50 100644
--- a/drivers/net/wireless/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/iwlwifi/pcie/trans.c
@@ -1270,6 +1270,8 @@ static int iwl_trans_pcie_wait_txq_empty(struct iwl_trans *trans, u32 txq_bm)
/* waiting for all the tx frames complete might take a while */
for (cnt = 0; cnt < trans->cfg->base_params->num_of_queues; cnt++) {
+ u8 wr_ptr;
+
if (cnt == trans_pcie->cmd_queue)
continue;
if (!test_bit(cnt, trans_pcie->queue_used))
@@ -1278,9 +1280,19 @@ static int iwl_trans_pcie_wait_txq_empty(struct iwl_trans *trans, u32 txq_bm)
continue;
txq = &trans_pcie->txq[cnt];
q = &txq->q;
- while (q->read_ptr != q->write_ptr && !time_after(jiffies,
- now + msecs_to_jiffies(IWL_FLUSH_WAIT_MS)))
+ wr_ptr = ACCESS_ONCE(q->write_ptr);
+
+ while (q->read_ptr != ACCESS_ONCE(q->write_ptr) &&
+ !time_after(jiffies,
+ now + msecs_to_jiffies(IWL_FLUSH_WAIT_MS))) {
+ u8 write_ptr = ACCESS_ONCE(q->write_ptr);
+
+ if (WARN_ONCE(wr_ptr != write_ptr,
+ "WR pointer moved while flushing %d -> %d\n",
+ wr_ptr, write_ptr))
+ return -ETIMEDOUT;
msleep(1);
+ }
if (q->read_ptr != q->write_ptr) {
IWL_ERR(trans,
--
1.8.3.2
--
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