2013-07-01 21:08:25

by Larry Finger

[permalink] [raw]
Subject: [PATCH] brcmsmac: Fix WARNING caused by lack of calls to dma_mapping_error()

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 <[email protected]>
Cc: Stable <[email protected]>
Cc: Brett Rudley <[email protected]>
Cc: Arend van Spriel <[email protected]>
Cc: Franky (Zhenhui) Lin <[email protected]>
Cc: Hante Meuleman <[email protected]>
Cc: [email protected]
---

drivers/net/wireless/brcm80211/brcmsmac/dma.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/brcm80211/brcmsmac/dma.c b/drivers/net/wireless/brcm80211/brcmsmac/dma.c
index 1860c57..6260571 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 is 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 +1287,8 @@ 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(dma_mapping_error(di->dmadev, pa))
+ 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
--
1.8.1.4



2013-07-19 10:03:23

by Arend van Spriel

[permalink] [raw]
Subject: Re: [PATCH] brcmsmac: Fix WARNING caused by lack of calls to dma_mapping_error()

Hi Larry,

Found it catching dust in a corner of my mailbox ;-)

Regards,
Arend

On 07/02/2013 10:47 AM, Arend van Spriel wrote:
> On 07/01/2013 11:08 PM, Larry Finger wrote:
>> 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.
>
> Thanks, Larry
>
> I think there a bugzilla issue for this that you might want to reference:
>
> https://bugzilla.kernel.org/show_bug.cgi?id=60261
>
>> Signed-off-by: Larry Finger <[email protected]>
>> Cc: Stable <[email protected]>
>> Cc: Brett Rudley <[email protected]>
>> Cc: Arend van Spriel <[email protected]>
>> Cc: Franky (Zhenhui) Lin <[email protected]>
>> Cc: Hante Meuleman <[email protected]>
>> Cc: [email protected]
>> ---
>>
>> drivers/net/wireless/brcm80211/brcmsmac/dma.c | 12 ++++++++----
>> 1 file changed, 8 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/net/wireless/brcm80211/brcmsmac/dma.c
>> b/drivers/net/wireless/brcm80211/brcmsmac/dma.c
>> index 1860c57..6260571 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 is refill failed completely or dma mapping failed.
>> The ring
>
> Missed some polishing opportunity: return false is refill... -> return
> false if refill...
>
>> + * 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 +1287,8 @@ 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(dma_mapping_error(di->dmadev, pa))
>> + return;
>
> I think the caller(s) should be informed or silently free the sk_buff
> here so we are not leaking it.
>
>> /* 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
>>
>
> Regards,
> Arend



2013-07-02 08:47:30

by Arend van Spriel

[permalink] [raw]
Subject: Re: [PATCH] brcmsmac: Fix WARNING caused by lack of calls to dma_mapping_error()

On 07/01/2013 11:08 PM, Larry Finger wrote:
> 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.

Thanks, Larry

I think there a bugzilla issue for this that you might want to reference:

https://bugzilla.kernel.org/show_bug.cgi?id=60261

> Signed-off-by: Larry Finger <[email protected]>
> Cc: Stable <[email protected]>
> Cc: Brett Rudley <[email protected]>
> Cc: Arend van Spriel <[email protected]>
> Cc: Franky (Zhenhui) Lin <[email protected]>
> Cc: Hante Meuleman <[email protected]>
> Cc: [email protected]
> ---
>
> drivers/net/wireless/brcm80211/brcmsmac/dma.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/wireless/brcm80211/brcmsmac/dma.c b/drivers/net/wireless/brcm80211/brcmsmac/dma.c
> index 1860c57..6260571 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 is refill failed completely or dma mapping failed. The ring

Missed some polishing opportunity: return false is refill... -> return
false if refill...

> + * 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 +1287,8 @@ 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(dma_mapping_error(di->dmadev, pa))
> + return;

I think the caller(s) should be informed or silently free the sk_buff
here so we are not leaking it.

> /* 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
>

Regards,
Arend


2013-07-02 12:37:37

by Neil Horman

[permalink] [raw]
Subject: Re: [PATCH] brcmsmac: Fix WARNING caused by lack of calls to dma_mapping_error()

On Tue, Jul 02, 2013 at 10:47:13AM +0200, Arend van Spriel wrote:
> On 07/01/2013 11:08 PM, Larry Finger wrote:
> >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.
>
> Thanks, Larry
>
> I think there a bugzilla issue for this that you might want to reference:
>
> https://bugzilla.kernel.org/show_bug.cgi?id=60261
>
Thanks Larry, you beat me too it, feel free to reassign the bz to yourself. :)

> >Signed-off-by: Larry Finger <[email protected]>
> >Cc: Stable <[email protected]>
> >Cc: Brett Rudley <[email protected]>
> >Cc: Arend van Spriel <[email protected]>
> >Cc: Franky (Zhenhui) Lin <[email protected]>
> >Cc: Hante Meuleman <[email protected]>
> >Cc: [email protected]
> >---
> >
> > drivers/net/wireless/brcm80211/brcmsmac/dma.c | 12 ++++++++----
> > 1 file changed, 8 insertions(+), 4 deletions(-)
> >
> >diff --git a/drivers/net/wireless/brcm80211/brcmsmac/dma.c b/drivers/net/wireless/brcm80211/brcmsmac/dma.c
> >index 1860c57..6260571 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 is refill failed completely or dma mapping failed. The ring
>
> Missed some polishing opportunity: return false is refill... ->
> return false if refill...
>
> >+ * 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;
Hmm, wouldn't it be better to set ring_empty to false and break out of the for
loop here, in the event that you partially refilled the ring? Otherwise, a
single dma mapping failure would let some useable descriptors go unused.

Neil

2013-07-01 21:13:06

by Hauke Mehrtens

[permalink] [raw]
Subject: Re: [PATCH] brcmsmac: Fix WARNING caused by lack of calls to dma_mapping_error()

On 07/01/2013 11:08 PM, Larry Finger wrote:
> 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 <[email protected]>
> Cc: Stable <[email protected]>
> Cc: Brett Rudley <[email protected]>
> Cc: Arend van Spriel <[email protected]>
> Cc: Franky (Zhenhui) Lin <[email protected]>
> Cc: Hante Meuleman <[email protected]>
> Cc: [email protected]
> ---
>
> drivers/net/wireless/brcm80211/brcmsmac/dma.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/wireless/brcm80211/brcmsmac/dma.c b/drivers/net/wireless/brcm80211/brcmsmac/dma.c
> index 1860c57..6260571 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 is 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))
^^
missing space

> + return false;
>
> /* save the free packet pointer */
> di->rxp[rxout] = p;
> @@ -1284,7 +1287,8 @@ 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(dma_mapping_error(di->dmadev, pa))
^^
missing space

> + 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
>