cxgb3 - Recovery from HW starvation of response queue entries.

Improve the traffic recovery after the HW ran out of response queue entries.

Signed-off-by: Divy Le Ray <divy@chelsio.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

2 files changed, 16 insertions, 1 deletions

diff --git a/drivers/net/cxgb3/adapter.h b/drivers/net/cxgb3/adapter.h
index 5c97a64451ce..01b99b901434 100644
--- a/drivers/net/cxgb3/adapter.h
+++ b/drivers/net/cxgb3/adapter.h
@@ -121,6 +121,8 @@ struct sge_rspq {		/* state for an SGE response queue */
         unsigned long empty;    /* # of times queue ran out of credits */
         unsigned long nomem;    /* # of responses deferred due to no mem */
         unsigned long unhandled_irqs;   /* # of spurious intrs */
+        unsigned long starved;
+        unsigned long restarted;
 };
 
 struct tx_desc;
diff --git a/drivers/net/cxgb3/sge.c b/drivers/net/cxgb3/sge.c
index 822a598c0db1..4ff0ab60c6c7 100644
--- a/drivers/net/cxgb3/sge.c
+++ b/drivers/net/cxgb3/sge.c
@@ -2376,13 +2376,26 @@ static void sge_timer_cb(unsigned long data)
                 spin_unlock(&qs->txq[TXQ_OFLD].lock);
         }
         lock = (adap->flags & USING_MSIX) ? &qs->rspq.lock :
-            &adap->sge.qs[0].rspq.lock;
+                                            &adap->sge.qs[0].rspq.lock;
         if (spin_trylock_irq(lock)) {
                 if (!napi_is_scheduled(qs->netdev)) {
+                        u32 status = t3_read_reg(adap, A_SG_RSPQ_FL_STATUS);
+
                         if (qs->fl[0].credits < qs->fl[0].size)
                                 __refill_fl(adap, &qs->fl[0]);
                         if (qs->fl[1].credits < qs->fl[1].size)
                                 __refill_fl(adap, &qs->fl[1]);
+
+                        if (status & (1 << qs->rspq.cntxt_id)) {
+                                qs->rspq.starved++;
+                                if (qs->rspq.credits) {
+                                        refill_rspq(adap, &qs->rspq, 1);
+                                        qs->rspq.credits--;
+                                        qs->rspq.restarted++;
+                                        t3_write_reg(adap, A_SG_RSPQ_FL_STATUS, 
+                                                     1 << qs->rspq.cntxt_id);
+                                }
+                        }
                 }
                 spin_unlock_irq(lock);
         }