Re: [bug] CONFIG_I2C_VIAPRO=y breaks skge

[Ingo Molnar <mingo@elte.hu>]

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* Jean Delvare <khali@linux-fr.org> wrote:

> Hi Ingo,
> 
> On Tue, 27 Jan 2009 16:13:59 +0100, Ingo Molnar wrote:
> > A -tip testsystem triggered this stuck eth0/skge bug today:
> > 
> >  [   24.787761] skge eth0: enabling interface
> >  [   24.793177] skge eth0: phy write timeout
> >  [   24.797035] skge eth0: phy write timeout
> >  [   24.801019] skge eth0: phy write timeout
> >  [   24.808325] skge eth0: phy write timeout
> >  [   24.813019] skge eth0: phy write timeout
> >  [   24.817019] skge eth0: phy write timeout
> >  [   24.821131] skge eth0: phy write timeout
> >  [   24.828610] skge eth0: phy write timeout
> >  [   24.832834] ADDRCONF(NETDEV_UP): eth0: link is not ready
> > 
> >  [root@centauri ~]# ifconfig 
> >  eth0     Link encap:Ethernet  HWaddr 00:0C:6E:B3:3D:C6  
> >           inet addr:10.0.1.22  Bcast:10.0.1.255  Mask:255.255.255.0
> >           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
> >           RX packets:12884901885 errors:0 dropped:0 overruns:0 frame:0
> >           TX packets:12884901885 errors:0 dropped:0 overruns:0 carrier:4294967295
> >           collisions:4294967295 txqueuelen:1000 
> >           RX bytes:18446744073709551615 (1.5 EiB)  TX bytes:18446744073709551615 (1.5 EiB)
> >           Interrupt:17 
> > 
> > (see the weird stats as well)
> > 
> > after a lengthy .config-bisection session i tracked it down to:
> > 
> >    CONFIG_I2C_VIAPRO=y
> > 
> > if that is disabled, the skge driver works fine and the stats look 
> > healthy:
> > 
> > eth0      Link encap:Ethernet  HWaddr 00:0C:6E:B3:3D:C6  
> >           inet addr:10.0.1.22  Bcast:10.0.1.255  Mask:255.255.255.0
> >           inet6 addr: fe80::20c:6eff:feb3:3dc6/64 Scope:Link
> >           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
> >           RX packets:837 errors:0 dropped:0 overruns:0 frame:0
> >           TX packets:767 errors:0 dropped:0 overruns:0 carrier:0
> >           collisions:0 txqueuelen:1000 
> >           RX bytes:128098 (125.0 KiB)  TX bytes:130996 (127.9 KiB)
> >           Interrupt:17 
> 
> Wow. This is hard to believe. The i2c-viapro driver only cares about the 
> SMBus interface of the VIA south bridge. I have a hard time imagining 
> how it could have any effect on networking.
> 
> Is the skge ethernet an on-board thing or an external adapter? I guess 
> the former. Do you have the detailed hardware specification for that 
> machine? I wonder if the ethernet chip could be somehow connected to the 
> SMBus.

on-board. No specification - it's an old testbox.

> Does the SMBus work on that machine? (Probably easier to test with 
> CONFIG_I2C_VIAPRO=m and CONFIG_I2C_CHARDEV=m.) I would also like to know 
> if there is anything in the logs when loading the i2c-viapro driver.

What's the best way to see whether the SMBus fully works on that machine?

> What I2C chip drivers did you include in your kernel? Presumably this is 
> a random config, so I can imagine that there is a chip on the SMBus to 
> which an I2C chip driver would have bound and that is causing the 
> problem, rather than i2c-viapro itself.

Correct, i found it via random config testing. x86 defconfig + VIAPRO 
enabled boots fine so it indeed could be interaction between i2c drivers.

I've attached:

 - the bad config - it does have a good deal of other I2C drivers enabled 
 - the good config
 - the bad bootlog
 - the good bootlog

> Can we please also have the output of lspci -nn?

Sure, find it below. [ Hm, why doesnt lspci default to -nn? ]

Anyway, this bug is not a big deal - i can work it around locally by 
excluding VIAPRO on that box. If you'd like to figure out why this happens 
that would be preferred of course, and i can send any debug info you need.

	Ingo

---------------->
00:00.0 Host bridge [0600]: VIA Technologies, Inc. VT8385 [K8T800 AGP] Host Bridge [1106:3188] (rev 01)
00:01.0 PCI bridge [0604]: VIA Technologies, Inc. VT8237 PCI bridge [K8T800/K8T890 South] [1106:b188]
00:07.0 FireWire (IEEE 1394) [0c00]: VIA Technologies, Inc. IEEE 1394 Host Controller [1106:3044] (rev 80)
00:0a.0 Ethernet controller [0200]: 3Com Corporation 3c940 10/100/1000Base-T [Marvell] [10b7:1700] (rev 12)
00:0d.0 Multimedia video controller [0400]: Brooktree Corporation Bt878 Video Capture [109e:036e] (rev 11)
00:0d.1 Multimedia controller [0480]: Brooktree Corporation Bt878 Audio Capture [109e:0878] (rev 11)
00:0f.0 RAID bus controller [0104]: VIA Technologies, Inc. VIA VT6420 SATA RAID Controller [1106:3149] (rev 80)
00:0f.1 IDE interface [0101]: VIA Technologies, Inc. VT82C586A/B/VT82C686/A/B/VT823x/A/C PIPC Bus Master IDE [1106:0571] (rev 06)
00:10.0 USB Controller [0c03]: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller [1106:3038] (rev 81)
00:10.1 USB Controller [0c03]: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller [1106:3038] (rev 81)
00:10.2 USB Controller [0c03]: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller [1106:3038] (rev 81)
00:10.3 USB Controller [0c03]: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller [1106:3038] (rev 81)
00:10.4 USB Controller [0c03]: VIA Technologies, Inc. USB 2.0 [1106:3104] (rev 86)
00:11.0 ISA bridge [0601]: VIA Technologies, Inc. VT8237 ISA bridge [KT600/K8T800/K8T890 South] [1106:3227]
00:11.5 Multimedia audio controller [0401]: VIA Technologies, Inc. VT8233/A/8235/8237 AC97 Audio Controller [1106:3059] (rev 60)
00:11.6 Communication controller [0780]: VIA Technologies, Inc. AC'97 Modem Controller [1106:3068] (rev 80)
00:18.0 Host bridge [0600]: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] HyperTransport Technology Configuration [1022:1100]
00:18.1 Host bridge [0600]: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Address Map [1022:1101]
00:18.2 Host bridge [0600]: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] DRAM Controller [1022:1102]
00:18.3 Host bridge [0600]: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Miscellaneous Control [1022:1103]
01:00.0 VGA compatible controller [0300]: ATI Technologies Inc RV280 [Radeon 9200 SE] [1002:5964] (rev 01)
01:00.1 Display controller [0380]: ATI Technologies Inc RV280 [Radeon 9200 SE] (Secondary) [1002:5d44] (rev 01)

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