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

login
register
mail settings
Submitter Larry Finger
Date July 1, 2013, 9:08 p.m.
Message ID <1372712883-4464-1-git-send-email-Larry.Finger@lwfinger.net>
Download mbox | patch
Permalink /patch/256223/
State Not Applicable
Delegated to: David Miller
Headers show

Comments

Larry Finger - July 1, 2013, 9:08 p.m.
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: Stable <stable@vger.kernel.org>
Cc: Brett Rudley <brudley@broadcom.com>
Cc: Arend van Spriel <arend@broadcom.com>
Cc: Franky (Zhenhui) Lin <frankyl@broadcom.com>
Cc: Hante Meuleman <meuleman@broadcom.com>
Cc: brcm80211-dev-list@broadcom.com
---

 drivers/net/wireless/brcm80211/brcmsmac/dma.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)
Hauke Mehrtens - July 1, 2013, 9:12 p.m.
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 <Larry.Finger@lwfinger.net>
> Cc: Stable <stable@vger.kernel.org>
> Cc: Brett Rudley <brudley@broadcom.com>
> Cc: Arend van Spriel <arend@broadcom.com>
> Cc: Franky (Zhenhui) Lin <frankyl@broadcom.com>
> Cc: Hante Meuleman <meuleman@broadcom.com>
> Cc: brcm80211-dev-list@broadcom.com
> ---
> 
>  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
> 

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Arend van Spriel - July 2, 2013, 8:47 a.m.
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 <Larry.Finger@lwfinger.net>
> Cc: Stable <stable@vger.kernel.org>
> Cc: Brett Rudley <brudley@broadcom.com>
> Cc: Arend van Spriel <arend@broadcom.com>
> Cc: Franky (Zhenhui) Lin <frankyl@broadcom.com>
> Cc: Hante Meuleman <meuleman@broadcom.com>
> Cc: brcm80211-dev-list@broadcom.com
> ---
>
>   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

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Neil Horman - July 2, 2013, 12:37 p.m.
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 <Larry.Finger@lwfinger.net>
> >Cc: Stable <stable@vger.kernel.org>
> >Cc: Brett Rudley <brudley@broadcom.com>
> >Cc: Arend van Spriel <arend@broadcom.com>
> >Cc: Franky (Zhenhui) Lin <frankyl@broadcom.com>
> >Cc: Hante Meuleman <meuleman@broadcom.com>
> >Cc: brcm80211-dev-list@broadcom.com
> >---
> >
> >  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
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Arend van Spriel - July 19, 2013, 10:03 a.m.
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 <Larry.Finger@lwfinger.net>
>> Cc: Stable <stable@vger.kernel.org>
>> Cc: Brett Rudley <brudley@broadcom.com>
>> Cc: Arend van Spriel <arend@broadcom.com>
>> Cc: Franky (Zhenhui) Lin <frankyl@broadcom.com>
>> Cc: Hante Meuleman <meuleman@broadcom.com>
>> Cc: brcm80211-dev-list@broadcom.com
>> ---
>>
>>   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


--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Patch

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