qede: qede_poll refactoring

This patch cleanups qede_poll() routine a bit
and allows qede_poll() to do single iteration to handle
TX completion [As under heavy TX load qede_poll() might
run for indefinite time in the while(1) loop for TX
completion processing and cause CPU stuck].

Signed-off-by: Manish <manish.chopra@qlogic.com>
Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/qlogic/qede/qede_main.c b/drivers/net/ethernet/qlogic/qede/qede_main.c
index ae4c53b401b74cc754f051ceb3fefe815d9424ae..9bc4c9f1a6c206f15167ffb7e595dda64b717133 100644 (file)
--- a/drivers/net/ethernet/qlogic/qede/qede_main.c
+++ b/drivers/net/ethernet/qlogic/qede/qede_main.c
@@ -1597,56 +1597,49 @@ next_cqe: /* don't consume bd rx buffer */
 
 static int qede_poll(struct napi_struct *napi, int budget)
 {
-       int work_done = 0;
        struct qede_fastpath *fp = container_of(napi, struct qede_fastpath,
-                                                napi);
+                                               napi);
        struct qede_dev *edev = fp->edev;
+       int rx_work_done = 0;
+       u8 tc;
 
-       while (1) {
-               u8 tc;
-
-               for (tc = 0; tc < edev->num_tc; tc++)
-                       if (qede_txq_has_work(&fp->txqs[tc]))
-                               qede_tx_int(edev, &fp->txqs[tc]);
-
-               if (qede_has_rx_work(fp->rxq)) {
-                       work_done += qede_rx_int(fp, budget - work_done);
-
-                       /* must not complete if we consumed full budget */
-                       if (work_done >= budget)
-                               break;
-               }
+       for (tc = 0; tc < edev->num_tc; tc++)
+               if (qede_txq_has_work(&fp->txqs[tc]))
+                       qede_tx_int(edev, &fp->txqs[tc]);
+
+       rx_work_done = qede_has_rx_work(fp->rxq) ?
+                       qede_rx_int(fp, budget) : 0;
+       if (rx_work_done < budget) {
+               qed_sb_update_sb_idx(fp->sb_info);
+               /* *_has_*_work() reads the status block,
+                * thus we need to ensure that status block indices
+                * have been actually read (qed_sb_update_sb_idx)
+                * prior to this check (*_has_*_work) so that
+                * we won't write the "newer" value of the status block
+                * to HW (if there was a DMA right after
+                * qede_has_rx_work and if there is no rmb, the memory
+                * reading (qed_sb_update_sb_idx) may be postponed
+                * to right before *_ack_sb). In this case there
+                * will never be another interrupt until there is
+                * another update of the status block, while there
+                * is still unhandled work.
+                */
+               rmb();
 
                /* Fall out from the NAPI loop if needed */
-               if (!(qede_has_rx_work(fp->rxq) || qede_has_tx_work(fp))) {
-                       qed_sb_update_sb_idx(fp->sb_info);
-                       /* *_has_*_work() reads the status block,
-                        * thus we need to ensure that status block indices
-                        * have been actually read (qed_sb_update_sb_idx)
-                        * prior to this check (*_has_*_work) so that
-                        * we won't write the "newer" value of the status block
-                        * to HW (if there was a DMA right after
-                        * qede_has_rx_work and if there is no rmb, the memory
-                        * reading (qed_sb_update_sb_idx) may be postponed
-                        * to right before *_ack_sb). In this case there
-                        * will never be another interrupt until there is
-                        * another update of the status block, while there
-                        * is still unhandled work.
-                        */
-                       rmb();
-
-                       if (!(qede_has_rx_work(fp->rxq) ||
-                             qede_has_tx_work(fp))) {
-                               napi_complete(napi);
-                               /* Update and reenable interrupts */
-                               qed_sb_ack(fp->sb_info, IGU_INT_ENABLE,
-                                          1 /*update*/);
-                               break;
-                       }
+               if (!(qede_has_rx_work(fp->rxq) ||
+                     qede_has_tx_work(fp))) {
+                       napi_complete(napi);
+
+                       /* Update and reenable interrupts */
+                       qed_sb_ack(fp->sb_info, IGU_INT_ENABLE,
+                                  1 /*update*/);
+               } else {
+                       rx_work_done = budget;
                }
        }
 
-       return work_done;
+       return rx_work_done;
 }
 
 static irqreturn_t qede_msix_fp_int(int irq, void *fp_cookie)