iwlwifi: tx-fail reported with zero retry count.

[Ben Greear <greearb@xxxxxxxxxxxxxxx>]

It seems that when tx fails (due to TX_STATUS_FAIL_LONG_LIMIT in this case), the
retry-count is sometimes reported as zero.  I would expect that it actually must have retried
many times (15 it seems?).  At least for fail-long-limit failures, is there a known constant amount of
times the firmware retransmits the frame before giving up?  If so, I can just hack that
value into the retry counter in this case.

Debug patch:

[greearb@ben-dt5 iwlwifi]$ git diff
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
index 1cddc65dd51e..6544dabb092b 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/tx.c
@@ -1929,8 +1929,14 @@ static void iwl_mvm_rx_tx_cmd_single(struct iwl_mvm *mvm,
                mvm->ethtool_stats.tx_mpdu_attempts += info->status.rates[0].count;
                mvm->ethtool_stats.tx_mpdu_retry += tx_resp->failure_frame;
                if (cb.flags & IWL_TX_CB_TXO_USED) {
+                       u32 idx = status & TX_STATUS_MSK;
+
                        mvm->ethtool_stats.txo_tx_mpdu_attempts += info->status.rates[0].count;
                        mvm->ethtool_stats.txo_tx_mpdu_retry += tx_resp->failure_frame;
+                       if (idx != TX_STATUS_SUCCESS) {
+                               pr_info("txo tx status failed: %d  tx_resp->failure_frame: %d\n",
+                                       idx, tx_resp->failure_frame);
+                       }
                }

                iwl_mvm_hwrate_to_tx_status(mvm, mvm->fw,


From dmesg:

Jun 06 06:29:40 ct523c-0b29 kernel: txo tx status failed: 131  tx_resp->failure_frame: 15
Jun 06 06:29:43 ct523c-0b29 kernel: txo tx status failed: 131  tx_resp->failure_frame: 15
Jun 06 06:29:48 ct523c-0b29 kernel: txo tx status failed: 131  tx_resp->failure_frame: 15
Jun 06 06:29:49 ct523c-0b29 kernel: txo tx status failed: 131  tx_resp->failure_frame: 15
Jun 06 06:29:52 ct523c-0b29 kernel: txo tx status failed: 131  tx_resp->failure_frame: 15
Jun 06 06:29:57 ct523c-0b29 kernel: txo tx status failed: 131  tx_resp->failure_frame: 0
Jun 06 06:29:57 ct523c-0b29 kernel: txo tx status failed: 131  tx_resp->failure_frame: 0
Jun 06 06:29:58 ct523c-0b29 kernel: txo tx status failed: 131  tx_resp->failure_frame: 0
Jun 06 06:30:01 ct523c-0b29 kernel: txo tx status failed: 131  tx_resp->failure_frame: 15
Jun 06 06:30:02 ct523c-0b29 kernel: txo tx status failed: 131  tx_resp->failure_frame: 15
Jun 06 06:30:03 ct523c-0b29 kernel: txo tx status failed: 131  tx_resp->failure_frame: 15
....


Thanks,
Ben

--
Ben Greear <greearb@xxxxxxxxxxxxxxx>
Candela Technologies Inc  http://www.candelatech.com