[ 3.8.y.z extended stable ] Patch "brcmsmac: Fix WARNING caused by lack of calls to dma_mapping_error()" has been added to staging queue

Kamal Mostafa kamal at canonical.com
Thu Sep 19 00:03:24 UTC 2013


This is a note to let you know that I have just added a patch titled

    brcmsmac: Fix WARNING caused by lack of calls to dma_mapping_error()

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.10.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 16d793f59f3135e8fd8cfcf6c208caacdc92bd09 Mon Sep 17 00:00:00 2001
From: "John W. Linville" <linville at tuxdriver.com>
Date: Fri, 9 Aug 2013 13:36:21 -0400
Subject: brcmsmac: Fix WARNING caused by lack of calls to dma_mapping_error()

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 at lwfinger.net>
Cc: Brett Rudley <brudley at broadcom.com>
Cc: Franky (Zhenhui) Lin <frankyl at broadcom.com>
Cc: Hante Meuleman <meuleman at broadcom.com>
Cc: brcm80211-dev-list at broadcom.com
Acked-by: Arend van Spriel <arend at broadcom.com>
Signed-off-by: John W. Linville <linville at tuxdriver.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/net/wireless/brcm80211/brcmsmac/dma.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/brcm80211/brcmsmac/dma.c b/drivers/net/wireless/brcm80211/brcmsmac/dma.c
index 1860c57..4fb9635 100644
--- a/drivers/net/wireless/brcm80211/brcmsmac/dma.c
+++ b/drivers/net/wireless/brcm80211/brcmsmac/dma.c
@@ -1015,9 +1015,10 @@ static bool dma64_txidle(struct dma_info *di)

 /*
  * 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)
 {
@@ -1078,6 +1079,8 @@ 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;
@@ -1284,7 +1287,11 @@ static void dma_txenq(struct dma_info *di, struct sk_buff *p)

 	/* 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
--
1.8.1.2





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