avoid uninitialised variable use in igc(4)

read icr reg before testing bit in result
add missing block in rxeof from ix

ok kevlo@ patrick@

diff --git a/sys/dev/pci/if_igc.c b/sys/dev/pci/if_igc.c
index 875a3eb..e66ca87 100644 (file)
--- a/sys/dev/pci/if_igc.c
+++ b/sys/dev/pci/if_igc.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: if_igc.c,v 1.4 2021/10/31 15:25:10 patrick Exp $      */
+/*     $OpenBSD: if_igc.c,v 1.5 2021/11/22 14:00:52 jsg Exp $  */
 /*-
  * SPDX-License-Identifier: BSD-2-Clause
  *
@@ -1283,7 +1283,7 @@ igc_rxeof(struct rx_ring *rxr)
        uint32_t ptype, staterr = 0;
        uint16_t len, vtag;
        uint8_t eop = 0;
-       int i;
+       int i, nextp;
 
        if (!ISSET(ifp->if_flags, IFF_RUNNING))
                return 0;
@@ -1342,6 +1342,17 @@ igc_rxeof(struct rx_ring *rxr)
                            if_rxr_inuse(&rxr->rx_ring), rxr->last_desc_filled);
                }
 
+               if (!eop) {
+                       /*
+                        * Figure out the next descriptor of this frame.
+                        */
+                       nextp = i + 1;
+                       if (nextp == sc->num_rx_desc)
+                               nextp = 0;
+                       nxbuf = &rxr->rx_buffers[nextp];
+                       /* prefetch(nxbuf); */
+               }
+
                mp->m_len = len;
 
                m = rxbuf->fmp;
@@ -1736,7 +1747,7 @@ int
 igc_intr_link(void *arg)
 {
        struct igc_softc *sc = (struct igc_softc *)arg;
-       uint32_t reg_icr;
+       uint32_t reg_icr = IGC_READ_REG(&sc->hw, IGC_ICR);
 
        if (reg_icr & IGC_ICR_LSC) {
                KERNEL_LOCK();