[ 18/40] brcmsmac: Fix WARNING caused by lack of calls to dma_mapping_error()

Greg Kroah-Hartman
2013-09-25T01:27:56Z

From: "John W. Linville" <linville@tuxdriver.com>

commit 67d0cf50bd32b66eab709871714e55725ee30ce4 upstream.

The driver fails to check the results of DMA mapping in twp places,
which results in the following warning:

[ 28.078515] ------------[ cut here ]------------
[ 28.078529] WARNING: at lib/dma-debug.c:937 check_unmap+0x47e/0x930()
[ 28.078533] bcma-pci-bridge 0000:0e:00.0: DMA-API: device driver failed to check map error[device address=0x00000000b5d60d6c] [size=1876 bytes] [mapped as
single]
[ 28.078536] Modules linked in: bnep bluetooth vboxpci(O) vboxnetadp(O) vboxnetflt(O) vboxdrv(O) ipv6 b43 brcmsmac rtl8192cu rtl8192c_common rtlwifi mac802
11 brcmutil cfg80211 snd_hda_codec_conexant rng_core snd_hda_intel kvm_amd snd_hda_codec ssb kvm mmc_core snd_pcm snd_seq snd_timer snd_seq_device snd k8temp
cordic joydev serio_raw hwmon sr_mod sg pcmcia pcmcia_core soundcore cdrom i2c_nforce2 i2c_core forcedeth bcma snd_page_alloc autofs4 ext4 jbd2 mbcache crc1
6 scsi_dh_alua scsi_dh_hp_sw scsi_dh_rdac scsi_dh_emc scsi_dh ata_generic pata_amd
[ 28.078602] CPU: 1 PID: 2570 Comm: NetworkManager Tainted: G O 3.10.0-rc7-wl+ #42
[ 28.078605] Hardware name: Hewlett-Packard HP Pavilion dv2700 Notebook PC/30D6, BIOS F.27 11/27/2008
[ 28.078607] 0000000000000009 ffff8800bbb03ad8 ffffffff8144f898 ffff8800bbb03b18
[ 28.078612] ffffffff8103e1eb 0000000000000002 ffff8800b719f480 ffff8800b7b9c010
[ 28.078617] ffffffff824204c0 ffffffff81754d57 0000000000000754 ffff8800bbb03b78
[ 28.078622] Call Trace:
[ 28.078624] <IRQ> [<ffffffff8144f898>] dump_stack+0x19/0x1b
[ 28.078634] [<ffffffff8103e1eb>] warn_slowpath_common+0x6b/0xa0
[ 28.078638] [<ffffffff8103e2c1>] warn_slowpath_fmt+0x41/0x50
[ 28.078650] [<ffffffff8122d7ae>] check_unmap+0x47e/0x930
[ 28.078655] [<ffffffff8122de4c>] debug_dma_unmap_page+0x5c/0x70
[ 28.078679] [<ffffffffa04a808c>] dma64_getnextrxp+0x10c/0x190 [brcmsmac]
[ 28.078691] [<ffffffffa04a9042>] dma_rx+0x62/0x240 [brcmsmac]
[ 28.078707] [<ffffffffa0479101>] brcms_c_dpc+0x211/0x9d0 [brcmsmac]
[ 28.078717] [<ffffffffa046d927>] ? brcms_dpc+0x27/0xf0 [brcmsmac]
[ 28.078731] [<ffffffffa046d947>] brcms_dpc+0x47/0xf0 [brcmsmac]
[ 28.078736] [<ffffffff81047dcc>] tasklet_action+0x6c/0xf0
--snip--
[ 28.078974] [<ffffffff813891bd>] SyS_sendmsg+0xd/0x20
[ 28.078979] [<ffffffff81455c24>] tracesys+0xdd/0xe2
[ 28.078982] ---[ end trace 6164d1a08148e9c8 ]---
[ 28.078984] Mapped at:
[ 28.078985] [<ffffffff8122c8fd>] debug_dma_map_page+0x9d/0x150
[ 28.078989] [<ffffffffa04a9322>] dma_rxfill+0x102/0x3d0 [brcmsmac]
[ 28.079001] [<ffffffffa047a13d>] brcms_c_init+0x87d/0x1100 [brcmsmac]
[ 28.079010] [<ffffffffa046d851>] brcms_init+0x21/0x30 [brcmsmac]
[ 28.079018] [<ffffffffa04786e0>] brcms_c_up+0x150/0x430 [brcmsmac]

As the patch adds a new failure mechanism to dma_rxfill(). When I changed the
comment at the start of the routine to add that information, I also polished
the wording.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Brett Rudley <brudley@broadcom.com>
Cc: Franky (Zhenhui) Lin <frankyl@broadcom.com>
Cc: Hante Meuleman <meuleman@broadcom.com>
Cc: brcm80211-dev-list@broadcom.com
Acked-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/net/wireless/brcm80211/brcmsmac/dma.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)

--- a/drivers/net/wireless/brcm80211/brcmsmac/dma.c
+++ b/drivers/net/wireless/brcm80211/brcmsmac/dma.c
@@ -1013,9 +1013,10 @@ static bool dma64_rxidle(struct dma_info

/*
* post receive buffers
- * return false is refill failed completely and ring is empty this will stall
- * the rx dma and user might want to call rxfill again asap. This unlikely
- * happens on memory-rich NIC, but often on memory-constrained dongle
+ * Return false if refill failed completely or dma mapping failed. The ring
+ * is empty, which will stall the rx dma and user might want to call rxfill
+ * again asap. This is unlikely to happen on a memory-rich NIC, but often on
+ * memory-constrained dongle.
*/
bool dma_rxfill(struct dma_pub *pub)
{
@@ -1074,6 +1075,8 @@ bool dma_rxfill(struct dma_pub *pub)

pa = dma_map_single(di->dmadev, p->data, di->rxbufsize,
DMA_FROM_DEVICE);
+ if (dma_mapping_error(di->dmadev, pa))
+ return false;

/* save the free packet pointer */
di->rxp[rxout] = p;
@@ -1294,7 +1297,11 @@ int dma_txfast(struct dma_pub *pub, stru

/* get physical address of buffer start */
pa = dma_map_single(di->dmadev, data, len, DMA_TO_DEVICE);
-
+ /* if mapping failed, free skb */
+ if (dma_mapping_error(di->dmadev, pa)) {
+ brcmu_pkt_buf_free_skb(p);
+ return;
+ }
/* With a DMA segment list, Descriptor table is filled
* using the segment list instead of looping over
* buffers in multi-chain DMA. Therefore, EOF for SGLIST