myri10ge: rework parity error check and cleanup

Clean up watchdog reset code:
 - move code that checks for stuck slice to a common routine
 - unless there is a confirmed h/w fault, verify that a stuck
   slice is still stuck in the watchdog worker; if the slice is no
   longer stuck, abort the reset.
 - this removes an egregious 2000ms pause in the watchdog worker that
   was a diagnostic aid (to look for spurious resets) the snuck into
   production code.

v3 includes corrections from Joe Perches

Signed-off-by: Jon Mason <mason@myri.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 60 insertions, 40 deletions

diff --git a/drivers/net/myri10ge/myri10ge.c b/drivers/net/myri10ge/myri10ge.c
index 0f0f83d50ddc..ca0345795fa6 100644
--- a/drivers/net/myri10ge/myri10ge.c
+++ b/drivers/net/myri10ge/myri10ge.c
@@ -193,6 +193,7 @@ struct myri10ge_slice_state {
         int watchdog_tx_done;
         int watchdog_tx_req;
         int watchdog_rx_done;
+        int stuck;
 #ifdef CONFIG_MYRI10GE_DCA
         int cached_dca_tag;
         int cpu;
@@ -3442,6 +3443,42 @@ static u32 myri10ge_read_reboot(struct myri10ge_priv *mgp)
         return reboot;
 }
 
+static void
+myri10ge_check_slice(struct myri10ge_slice_state *ss, int *reset_needed,
+                     int *busy_slice_cnt, u32 rx_pause_cnt)
+{
+        struct myri10ge_priv *mgp = ss->mgp;
+        int slice = ss - mgp->ss;
+
+        if (ss->tx.req != ss->tx.done &&
+            ss->tx.done == ss->watchdog_tx_done &&
+            ss->watchdog_tx_req != ss->watchdog_tx_done) {
+                /* nic seems like it might be stuck.. */
+                if (rx_pause_cnt != mgp->watchdog_pause) {
+                        if (net_ratelimit())
+                                netdev_warn(mgp->dev, "slice %d: TX paused, "
+                                            "check link partner\n", slice);
+                } else {
+                        netdev_warn(mgp->dev,
+                                    "slice %d: TX stuck %d %d %d %d %d %d\n",
+                                    slice, ss->tx.queue_active, ss->tx.req,
+                                    ss->tx.done, ss->tx.pkt_start,
+                                    ss->tx.pkt_done,
+                                    (int)ntohl(mgp->ss[slice].fw_stats->
+                                               send_done_count));
+                        *reset_needed = 1;
+                        ss->stuck = 1;
+                }
+        }
+        if (ss->watchdog_tx_done != ss->tx.done ||
+            ss->watchdog_rx_done != ss->rx_done.cnt) {
+                *busy_slice_cnt += 1;
+        }
+        ss->watchdog_tx_done = ss->tx.done;
+        ss->watchdog_tx_req = ss->tx.req;
+        ss->watchdog_rx_done = ss->rx_done.cnt;
+}
+
 /*
  * This watchdog is used to check whether the board has suffered
  * from a parity error and needs to be recovered.
@@ -3450,10 +3487,12 @@ static void myri10ge_watchdog(struct work_struct *work)
 {
         struct myri10ge_priv *mgp =
             container_of(work, struct myri10ge_priv, watchdog_work);
-        struct myri10ge_tx_buf *tx;
-        u32 reboot;
+        struct myri10ge_slice_state *ss;
+        u32 reboot, rx_pause_cnt;
         int status, rebooted;
         int i;
+        int reset_needed = 0;
+        int busy_slice_cnt = 0;
         u16 cmd, vendor;
 
         mgp->watchdog_resets++;
@@ -3465,8 +3504,7 @@ static void myri10ge_watchdog(struct work_struct *work)
                  * For now, just report it */
                 reboot = myri10ge_read_reboot(mgp);
                 netdev_err(mgp->dev, "NIC rebooted (0x%x),%s resetting\n",
-                           reboot,
-                           myri10ge_reset_recover ? "" : " not");
+                           reboot, myri10ge_reset_recover ? "" : " not");
                 if (myri10ge_reset_recover == 0)
                         return;
                 rtnl_lock();
@@ -3498,23 +3536,24 @@ static void myri10ge_watchdog(struct work_struct *work)
                                 return;
                         }
                 }
-                /* Perhaps it is a software error.  Try to reset */
-
-                netdev_err(mgp->dev, "device timeout, resetting\n");
+                /* Perhaps it is a software error. See if stuck slice
+                 * has recovered, reset if not */
+                rx_pause_cnt = ntohl(mgp->ss[0].fw_stats->dropped_pause);
                 for (i = 0; i < mgp->num_slices; i++) {
-                        tx = &mgp->ss[i].tx;
-                        netdev_err(mgp->dev, "(%d): %d %d %d %d %d %d\n",
-                                   i, tx->queue_active, tx->req,
-                                   tx->done, tx->pkt_start, tx->pkt_done,
-                                   (int)ntohl(mgp->ss[i].fw_stats->
-                                              send_done_count));
-                        msleep(2000);
-                        netdev_info(mgp->dev, "(%d): %d %d %d %d %d %d\n",
-                                    i, tx->queue_active, tx->req,
-                                    tx->done, tx->pkt_start, tx->pkt_done,
-                                    (int)ntohl(mgp->ss[i].fw_stats->
-                                               send_done_count));
+                        ss = mgp->ss;
+                        if (ss->stuck) {
+                                myri10ge_check_slice(ss, &reset_needed,
+                                                     &busy_slice_cnt,
+                                                     rx_pause_cnt);
+                                ss->stuck = 0;
+                        }
                 }
+                if (!reset_needed) {
+                        netdev_dbg(mgp->dev, "not resetting\n");
+                        return;
+                }
+
+                netdev_err(mgp->dev, "device timeout, resetting\n");
         }
 
         if (!rebooted) {
@@ -3567,27 +3606,8 @@ static void myri10ge_watchdog_timer(unsigned long arg)
                             myri10ge_fill_thresh)
                                 ss->rx_big.watchdog_needed = 0;
                 }
-
-                if (ss->tx.req != ss->tx.done &&
-                    ss->tx.done == ss->watchdog_tx_done &&
-                    ss->watchdog_tx_req != ss->watchdog_tx_done) {
-                        /* nic seems like it might be stuck.. */
-                        if (rx_pause_cnt != mgp->watchdog_pause) {
-                                if (net_ratelimit())
-                                        netdev_err(mgp->dev, "slice %d: TX paused, check link partner\n",
-                                                   i);
-                        } else {
-                                netdev_warn(mgp->dev, "slice %d stuck:", i);
-                                reset_needed = 1;
-                        }
-                }
-                if (ss->watchdog_tx_done != ss->tx.done ||
-                    ss->watchdog_rx_done != ss->rx_done.cnt) {
-                        busy_slice_cnt++;
-                }
-                ss->watchdog_tx_done = ss->tx.done;
-                ss->watchdog_tx_req = ss->tx.req;
-                ss->watchdog_rx_done = ss->rx_done.cnt;
+                myri10ge_check_slice(ss, &reset_needed, &busy_slice_cnt,
+                                     rx_pause_cnt);
         }
         /* if we've sent or received no traffic, poll the NIC to
          * ensure it is still there.  Otherwise, we risk not noticing