From: kettenis <kettenis@openbsd.org>
Date: Fri, 22 May 2015 06:50:54 +0000 (+0000)
Subject: Limit the number of dma segments used for transmitting packets to
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=617b19c0ad47f30a05ea15c59f9c9c90662093d1;p=openbsd

Limit the number of dma segments used for transmitting packets to
IWM_NUM_OF_TBS - 2.  We have IWM_NUM_OF_TBS slots, but use two of those
for sending commands to the firmware.  Hopefully fixes the

  iwm0: hardware error, stopping device

errors I've seen somewhat regularly.

ok claudio@, deraadt@
---

diff --git a/sys/dev/pci/if_iwm.c b/sys/dev/pci/if_iwm.c
index 00ca5329e75..adb334fc623 100644
--- a/sys/dev/pci/if_iwm.c
+++ b/sys/dev/pci/if_iwm.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_iwm.c,v 1.40 2015/05/21 22:13:55 kettenis Exp $	*/
+/*	$OpenBSD: if_iwm.c,v 1.41 2015/05/22 06:50:54 kettenis Exp $	*/
 
 /*
  * Copyright (c) 2014 genua mbh <info@genua.de>
@@ -1113,7 +1113,8 @@ iwm_alloc_tx_ring(struct iwm_softc *sc, struct iwm_tx_ring *ring, int qid)
 		paddr += sizeof(struct iwm_device_cmd);
 
 		error = bus_dmamap_create(sc->sc_dmat, MCLBYTES,
-		    IWM_NUM_OF_TBS, MCLBYTES, 0, BUS_DMA_NOWAIT, &data->map);
+		    IWM_NUM_OF_TBS - 2, MCLBYTES, 0, BUS_DMA_NOWAIT,
+		    &data->map);
 		if (error != 0) {
 			printf("%s: could not create TX buf DMA map\n", DEVNAME(sc));
 			goto fail;