IB/ipath: HW workaround for case where chip can send but not receive

Workaround a QLE7140 problem that in rare cases causes flow control
problems after link recovery by forcing a link retrain after recovery.
A module parameter is provided to control the behavior in case it causes
problems.

Signed-off-by: Dave Olson <dave.olson@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_intr.c b/drivers/infiniband/hw/ipath/ipath_intr.c
index dde5dfc9fcf5..ed82ecbb02da 100644
--- a/drivers/infiniband/hw/ipath/ipath_intr.c
+++ b/drivers/infiniband/hw/ipath/ipath_intr.c
@@ -366,6 +366,22 @@ static void handle_e_ibstatuschanged(struct ipath_devdata *dd,
         dd->ipath_ibpollcnt = 0; /* not poll*, now */
         ipath_stats.sps_iblink++;
 
+        if (ibstate != init && dd->ipath_lastlinkrecov && ipath_linkrecovery) {
+                u64 linkrecov;
+                linkrecov = ipath_snap_cntr(dd,
+                        dd->ipath_cregs->cr_iblinkerrrecovcnt);
+                if (linkrecov != dd->ipath_lastlinkrecov) {
+                        ipath_dbg("IB linkrecov up %Lx (%s %s) recov %Lu\n",
+                                ibcs, ib_linkstate(dd, ibcs),
+                                ipath_ibcstatus_str[ltstate],
+                                linkrecov);
+                        /* and no more until active again */
+                        dd->ipath_lastlinkrecov = 0;
+                        ipath_set_linkstate(dd, IPATH_IB_LINKDOWN);
+                        goto skip_ibchange;
+                }
+        }
+
         if (ibstate == init || ibstate == arm || ibstate == active) {
                 *dd->ipath_statusp &= ~IPATH_STATUS_IB_NOCABLE;
                 if (ibstate == init || ibstate == arm) {
@@ -392,6 +408,8 @@ static void handle_e_ibstatuschanged(struct ipath_devdata *dd,
                                 IPATH_NOCABLE);
                         ipath_hol_down(dd);
                 } else {  /* active */
+                        dd->ipath_lastlinkrecov = ipath_snap_cntr(dd,
+                                dd->ipath_cregs->cr_iblinkerrrecovcnt);
                         *dd->ipath_statusp |=
                                 IPATH_STATUS_IB_READY | IPATH_STATUS_IB_CONF;
                         dd->ipath_flags |= IPATH_LINKACTIVE;