net/sfc: restart TxQ in case of exception on event queue

Examples of recoverable exceptions because of Tx error are:
 - Tx descriptor PCI read error
 - invalid Tx option descriptor
 - Tx option descriptor not supported by the firmware variant
 - unexpected Tx option descriptor (e.g. missing FATSO2A before
   FATSO2B, missing FATSO2B after FATSO2A)
 - incomplete packet push (CONT bit set in the latest pushed DMA
   descriptor)

Signed-off-by: Ivan Malov <ivan.malov@oktetlabs.ru>
Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
Reviewed-by: Andrew Lee <alee@solarflare.com>
Reviewed-by: Robert Stonehouse <rstonehouse@solarflare.com>

diff --git a/drivers/net/sfc/sfc_ev.c b/drivers/net/sfc/sfc_ev.c
index 36aede8..af3c7b2 100644 (file)
--- a/drivers/net/sfc/sfc_ev.c
+++ b/drivers/net/sfc/sfc_ev.c
@@ -339,6 +339,20 @@ sfc_ev_qpoll(struct sfc_evq *evq)
                                        rxq_sw_index);
                }
 
+               if (evq->txq != NULL) {
+                       unsigned int txq_sw_index = sfc_txq_sw_index(evq->txq);
+
+                       sfc_warn(sa,
+                                "restart TxQ %u because of exception on its EvQ %u",
+                                txq_sw_index, evq->evq_index);
+
+                       sfc_tx_qstop(sa, txq_sw_index);
+                       rc = sfc_tx_qstart(sa, txq_sw_index);
+                       if (rc != 0)
+                               sfc_err(sa, "cannot restart TxQ %u",
+                                       txq_sw_index);
+               }
+
                if (evq->exception)
                        sfc_panic(sa, "unrecoverable exception on EvQ %u",
                                  evq->evq_index);