Re: BCM4401 LAN

Re: BCM4401 LAN

[Michael Chan]

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On Wed, Nov 23, 2022 at 10:42 AM Ioannis Barkas <jnyb.de@gmail.com> wrote:
>
> Hello guys!
>
> I resurrected some old PCs at job and found one with BCM4401 LAN. This
> LAN had some issues as I read in various OSes so I gave it a try using
> live Ubuntu 22.10. It worked fine though I got this when I plugged in
> the Ethernet cable:
> [  517.928052] b44 ssb0:0 eth0: Link is up at 100 Mbps, full duplex
> [  517.928066] b44 ssb0:0 eth0: Flow control is off for TX and off for RX
> [  517.928246] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
> [  520.697405] ------------[ cut here ]------------
> [  520.697417] b44 0000:0a:0b.0: DMA addr 0x00000000766d9402+42
> overflow (mask 3fffffff, bus limit 0).
> [  520.697438] WARNING: CPU: 1 PID: 1187 at kernel/dma/direct.h:97
> dma_direct_map_page+0x1f1/0x200

I think you get this one-time warning because the DMA address is
higher than the 30-bit DMA address supported by the chip.  But the
driver will see the error returned from dma_map_single() and it will
copy the data to a bounce buffer.  So it should work fine despite this
alarming warning.

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Re: BCM4401 LAN

[Francois Romieu]

(MAINTAINERS file suggests to Cc: Michael Chan Cced as b44 maintainer)

Ioannis Barkas <jnyb.de@gmail.com> :
[...]
> I resurrected some old PCs at job and found one with BCM4401 LAN. This
> LAN had some issues as I read in various OSes so I gave it a try using
> live Ubuntu 22.10. It worked fine though I got this when I plugged in
> the Ethernet cable:
> [  517.928052] b44 ssb0:0 eth0: Link is up at 100 Mbps, full duplex
> [  517.928066] b44 ssb0:0 eth0: Flow control is off for TX and off for RX
> [  517.928246] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
> [  520.697405] ------------[ cut here ]------------
> [  520.697417] b44 0000:0a:0b.0: DMA addr 0x00000000766d9402+42
> overflow (mask 3fffffff, bus limit 0).
> [  520.697438] WARNING: CPU: 1 PID: 1187 at kernel/dma/direct.h:97
> dma_direct_map_page+0x1f1/0x200
> [  520.697456] Modules linked in: ntfs3 snd_seq_dummy snd_hrtimer
> binfmt_misc zfs(PO) zunicode(PO) zzstd(O) zlua(O) zavl(PO) icp(PO)
> zcommon(PO) znvpair(PO) spl(O) snd_intel8x0 snd_ac97_codec ac97_bus
[...]
> This is the LAN device:
> 0a:0b.0 Ethernet controller [0200]: Broadcom Inc. and subsidiaries
> BCM4401-B0 100Base-TX [14e4:170c] (rev 02)
>     Subsystem: Lenovo BCM4401-B0 100Base-TX [17aa:1004]
>     Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop-
> ParErr- Stepping- SERR+ FastB2B- DisINTx-
>     Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort-
> <TAbort- <MAbort- >SERR- <PERR- INTx-
>     Latency: 32
>     Interrupt: pin A routed to IRQ 23
>     Region 0: Memory at d0000000 (32-bit, non-prefetchable) [size=8K]
>     Capabilities: [40] Power Management version 2
>         Flags: PMEClk- DSI- D1+ D2+ AuxCurrent=0mA
> PME(D0+,D1+,D2+,D3hot+,D3cold+)
>         Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=2 PME-
>     Kernel driver in use: b44
>     Kernel modules: b44
[...]
> Does anything look awfully wrong in the trace?

See kernel/dma/direct.c::dma_direct_map_resource for a WARN_ON_ONCE
message related to the comment below in drivers/net/ethernet/broadcom/b44.c

static netdev_tx_t b44_start_xmit(struct sk_buff *skb, struct net_device *dev)
[...]
        mapping = dma_map_single(bp->sdev->dma_dev, skb->data, len, DMA_TO_DEVICE);
        if (dma_mapping_error(bp->sdev->dma_dev, mapping) || mapping + len > DMA_BIT_MASK(30)) {
                struct sk_buff *bounce_skb;

                /* Chip can't handle DMA to/from >1GB, use bounce buffer */
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                if (!dma_mapping_error(bp->sdev->dma_dev, mapping))
                        dma_unmap_single(bp->sdev->dma_dev, mapping, len, 
                                             DMA_TO_DEVICE);

It's a bit less than optimal performance-wise but it is expected to work.

This one was rather trivial but please avoid requests related to giant
out-of-tree (zfs) module tainted kernel in the future.

-- 
Ueimor

BCM4401 LAN

[Ioannis Barkas]

Hello guys!

I resurrected some old PCs at job and found one with BCM4401 LAN. This
LAN had some issues as I read in various OSes so I gave it a try using
live Ubuntu 22.10. It worked fine though I got this when I plugged in
the Ethernet cable:
[  517.928052] b44 ssb0:0 eth0: Link is up at 100 Mbps, full duplex
[  517.928066] b44 ssb0:0 eth0: Flow control is off for TX and off for RX
[  517.928246] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[  520.697405] ------------[ cut here ]------------
[  520.697417] b44 0000:0a:0b.0: DMA addr 0x00000000766d9402+42
overflow (mask 3fffffff, bus limit 0).
[  520.697438] WARNING: CPU: 1 PID: 1187 at kernel/dma/direct.h:97
dma_direct_map_page+0x1f1/0x200
[  520.697456] Modules linked in: ntfs3 snd_seq_dummy snd_hrtimer
binfmt_misc zfs(PO) zunicode(PO) zzstd(O) zlua(O) zavl(PO) icp(PO)
zcommon(PO) znvpair(PO) spl(O) snd_intel8x0 snd_ac97_codec ac97_bus
snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq input_leds
snd_seq_device intel_powerclamp serio_raw snd_timer snd mac_hid
soundcore msr parport_pc ppdev lp parport ramoops pstore_blk
reed_solomon pstore_zone efi_pstore ip_tables x_tables autofs4 overlay
isofs dm_mirror dm_region_hash dm_log uas usb_storage i915 drm_buddy
i2c_algo_bit ttm drm_display_helper cec rc_core drm_kms_helper
gpio_ich syscopyarea sysfillrect sysimgblt fb_sys_fops hid_generic drm
b44 psmouse ssb i2c_i801 lpc_ich i2c_smbus video mii pata_acpi floppy
usbhid hid
[  520.697639] CPU: 1 PID: 1187 Comm: NetworkManager Tainted: P
   O      5.19.0-21-generic #21-Ubuntu
[  520.697648] Hardware name: LENOVO 832676G/LENOVO, BIOS 2HKT13AUS 09/08/2006
[  520.697652] RIP: 0010:dma_direct_map_page+0x1f1/0x200
[  520.697663] Code: 89 e7 48 89 55 c8 e8 be 0b 7f 00 4d 89 e9 48 8d
4d d0 48 89 da 41 56 4c 8b 45 c8 48 89 c6 48 c7 c7 28 13 80 b3 e8 04
d6 cc 00 <0f> 0b 58 eb 87 e8 15 29 d9 00 0f 1f 44 00 00 0f 1f 44 00 00
55 48
[  520.697670] RSP: 0018:ffffafd740b3b9d0 EFLAGS: 00010046
[  520.697677] RAX: 0000000000000000 RBX: ffff943701b01670 RCX: 0000000000000000
[  520.697681] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[  520.697685] RBP: ffffafd740b3ba18 R08: 0000000000000000 R09: 0000000000000000
[  520.697688] R10: 0000000000000000 R11: 0000000000000000 R12: ffff9437019d60d0
[  520.697692] R13: 000000003fffffff R14: 0000000000000000 R15: ffff94370ab25000
[  520.697697] FS:  00007fdf897554c0(0000) GS:ffff9437bc300000(0000)
knlGS:0000000000000000
[  520.697702] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  520.697707] CR2: 000055ecba997230 CR3: 00000000080b6000 CR4: 00000000000006e0
[  520.697713] Call Trace:
[  520.697718]  <TASK>
[  520.697728]  dma_map_page_attrs+0x63/0xa0
[  520.697740]  b44_start_xmit+0xd7/0x532 [b44]
[  520.697756]  dev_hard_start_xmit+0x68/0x1e0
[  520.697767]  sch_direct_xmit+0x10b/0x330
[  520.697776]  __dev_xmit_skb+0x397/0x5a0
[  520.697782]  ? _copy_from_iter+0x9a/0x6a0
[  520.697793]  __dev_queue_xmit+0x332/0x6e0
[  520.697801]  ? packet_parse_headers+0x16d/0x260
[  520.697811]  ? packet_parse_headers+0x16d/0x260
[  520.697819]  dev_queue_xmit+0xb/0x20
[  520.697825]  packet_snd+0x332/0x7b0
[  520.697834]  packet_sendmsg+0x30/0x40
[  520.697841]  sock_sendmsg+0x6d/0x70
[  520.697850]  __sys_sendto+0x142/0x1a0
[  520.697864]  __x64_sys_sendto+0x24/0x40
[  520.697872]  do_syscall_64+0x5b/0x90
[  520.697880]  ? exit_to_user_mode_prepare+0x30/0xb0
[  520.697889]  ? syscall_exit_to_user_mode+0x26/0x50
[  520.697897]  ? __x64_sys_read+0x19/0x30
[  520.697905]  ? do_syscall_64+0x67/0x90
[  520.697911]  ? do_syscall_64+0x67/0x90
[  520.697917]  ? ksys_write+0xe6/0x100
[  520.697925]  ? exit_to_user_mode_prepare+0x30/0xb0
[  520.697935]  ? syscall_exit_to_user_mode+0x26/0x50
[  520.697942]  ? __x64_sys_write+0x19/0x30
[  520.697949]  ? do_syscall_64+0x67/0x90
[  520.697956]  ? syscall_exit_to_user_mode+0x26/0x50
[  520.697962]  ? __do_sys_gettid+0x1b/0x30
[  520.697970]  ? do_syscall_64+0x67/0x90
[  520.697975]  ? sysvec_apic_timer_interrupt+0x4b/0xd0
[  520.697981]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[  520.697990] RIP: 0033:0x7fdf8a8a39cc
[  520.697998] Code: 4a b8 f6 ff 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5
44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24
08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 90 b8 f6 ff
48 8b
[  520.698003] RSP: 002b:00007ffeaecdc9e0 EFLAGS: 00000293 ORIG_RAX:
000000000000002c
[  520.698010] RAX: ffffffffffffffda RBX: 000055ecba989780 RCX: 00007fdf8a8a39cc
[  520.698015] RDX: 000000000000001c RSI: 00007ffeaecdca40 RDI: 000000000000001a
[  520.698019] RBP: 0000000000000000 R08: 00007ffeaecdca20 R09: 0000000000000014
[  520.698023] R10: 0000000000004000 R11: 0000000000000293 R12: 000055ecba93d340
[  520.698026] R13: 000055ecba9897b0 R14: 000000793c171530 R15: 00007ffeaecdcb00
[  520.698036]  </TASK>
[  520.698039] ---[ end trace 0000000000000000 ]---

This is the LAN device:
0a:0b.0 Ethernet controller [0200]: Broadcom Inc. and subsidiaries
BCM4401-B0 100Base-TX [14e4:170c] (rev 02)
    Subsystem: Lenovo BCM4401-B0 100Base-TX [17aa:1004]
    Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop-
ParErr- Stepping- SERR+ FastB2B- DisINTx-
    Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort-
<TAbort- <MAbort- >SERR- <PERR- INTx-
    Latency: 32
    Interrupt: pin A routed to IRQ 23
    Region 0: Memory at d0000000 (32-bit, non-prefetchable) [size=8K]
    Capabilities: [40] Power Management version 2
        Flags: PMEClk- DSI- D1+ D2+ AuxCurrent=0mA
PME(D0+,D1+,D2+,D3hot+,D3cold+)
        Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=2 PME-
    Kernel driver in use: b44
    Kernel modules: b44
00: e4 14 0c 17 06 01 10 00 02 00 00 02 00 20 00 00
10: 00 00 00 d0 00 00 00 00 00 00 00 00 00 00 00 00
20: 00 00 00 00 00 00 00 00 00 00 00 00 aa 17 04 10
30: 00 00 00 00 40 00 00 00 00 00 00 00 0b 01 00 00
40: 01 00 02 fe 00 40 00 34 00 00 00 00 00 00 00 00
50: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
70: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
80: 00 00 00 18 00 00 00 00 00 00 00 00 00 00 00 00
90: 00 00 00 00 00 01 00 00 00 00 00 00 00 00 00 00
a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
b0: 00 00 00 00 40 00 00 00 c0 00 00 00 00 00 00 00
c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Does anything look awfully wrong in the trace?

Re: BCM4401 LAN

[Ioannis Barkas]

Hello,

thank you for your replies. Now I understand what happens. It is an
old chip having a hw limit though it was used on a 64-bit machine
having much more memory than the LAN IC limit. As you said, it worked
fine without any issue.

Take care!