Fix nic lock usage around iwm_disable_rx_dma().

iwm_disable_rx_dma() was unintentionally releasing the nic lock too early.
Patch by Imre Vadasz.

diff --git a/sys/dev/pci/if_iwm.c b/sys/dev/pci/if_iwm.c
index a7332b4..13e2974 100644 (file)
--- a/sys/dev/pci/if_iwm.c
+++ b/sys/dev/pci/if_iwm.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: if_iwm.c,v 1.168 2017/04/21 16:39:52 stsp Exp $       */
+/*     $OpenBSD: if_iwm.c,v 1.169 2017/04/21 16:40:11 stsp Exp $       */
 
 /*
  * Copyright (c) 2014, 2016 genua gmbh <info@genua.de>
@@ -1646,12 +1646,14 @@ iwm_nic_config(struct iwm_softc *sc)
 int
 iwm_nic_rx_init(struct iwm_softc *sc)
 {
-       if (!iwm_nic_lock(sc))
-               return EBUSY;
-
        memset(sc->rxq.stat, 0, sizeof(*sc->rxq.stat));
 
        iwm_disable_rx_dma(sc);
+
+       if (!iwm_nic_lock(sc))
+               return EBUSY;
+
+       /* reset and flush pointers */
        IWM_WRITE(sc, IWM_FH_MEM_RCSR_CHNL0_RBDCB_WPTR, 0);
        IWM_WRITE(sc, IWM_FH_MEM_RCSR_CHNL0_FLUSH_RB_REQ, 0);
        IWM_WRITE(sc, IWM_FH_RSCSR_CHNL0_RDPTR, 0);