i2c vs nVidia [Re: 2.6.21-rc2-mm1]

J.A. Magallón
2007-03-06T00:17:10Z

On Fri, 2 Mar 2007 03:00:26 -0800, Andrew Morton <akpm@linux-foundation.org> wrote:

>
> Temporarily at
>
> http://userweb.kernel.org/~akpm/2.6.21-rc2-mm1/
>

More things...

Yes, this is related to nVidia driver. First of all, I'm not asking for help
for a broken closed-source driver. I just want Linux to be fool^^^^bullet-proof ;).

As one can expect from a closed-source driver, recent changes in Linux broke it.
New nVidia drivers include some i2c sensors. The driver worked till 2.6.20-rc6-mm3.
Since then, I can't use them. I have tracked down the problem to i2c.
nVidia driver tries to create 3 i2c devices, and I get this:

**WARNING** I2C adapter driver [NVIDIA i2c adapter 0 at 1:00.0] forgot to specify physical device; fix it!
i2c-10: attach_adapter failed (-16) for driver [w83627hf]
**WARNING** I2C adapter driver [NVIDIA i2c adapter 1 at 1:00.0] forgot to specify physical device; fix it!
i2c-11: attach_adapter failed (-16) for driver [w83627hf]
**WARNING** I2C adapter driver [NVIDIA i2c adapter 2 at 1:00.0] forgot to specify physical device; fix it!
i2c-12: attach_adapter failed (-16) for driver [w83627hf]

Two problems arise:
- The directories in /sys/class/i2c-adapter/ are created, but trying to ls
its contents oopses:

last sysfs file: class/i2c-adapter/i2c-0/name
Modules linked in: nvidia(P) nfsd exportfs lockd nfs_acl sunrpc snd_intel8x0 snd_ens1371 gameport snd_rawmidi snd_ac97_codec w83627hf ac97_bus hwmon_vid snd_pcm hwmon snd_timer i2c_isa snd_page_alloc i2c_i801 snd i2c_dev loop intel_agp agpgart udf e1000 3c59x microcode ohci1394 ieee1394 usblp evdev
CPU: 3
EIP: 0060:[<c0194b0c>] Tainted: P VLI
EFLAGS: 00010202 (2.6.20-jam01 #1)
EIP is at sysfs_follow_link+0xe6/0x254
eax: 00020b36 ebx: f329edd8 ecx: 00000000 edx: f4ab84d8
esi: f0df4ee8 edi: 00000100 ebp: 00000002 esp: f4039ea4
ds: 007b es: 007b fs: 00d8 gs: 0033 ss: 0068
Process sensors (pid: 4991, ti=f4038000 task=f7efa540 task.ti=f4038000)
Stack: f7ee4338 f4039edc f0ef7000 ffffffea f4ab84d8 00000000 c0387128 00000000
c02f76a0 f329edd8 00000100 bfd2b6fc c0162b12 00000000 00000000 00000000
00000000 00000000 45eb5857 1f6efe56 c2235fc0 00000000 f4039f44 c011c434
Call Trace:
[<c0162b12>] generic_readlink+0x27/0x6e
[<c011c434>] timespec_trunc+0x18/0x5d
[<c011ca11>] current_fs_time+0x41/0x50
[<c015f43a>] sys_readlinkat+0x61/0x7a
[<c015f47a>] sys_readlink+0x27/0x2b
[<c01027ee>] sysenter_past_esp+0x5f/0x85
[<c02f0000>] __down_interruptible+0xa2/0x10e
=======================
Code: 24 18 b8 00 b2 39 c0 e8 6e ba 15 00 8b 44 24 18 85 c0 0f 84 42 01 00 00 b8 cc ee 37 c0 e8 dd 73 f9 ff 8b 44 24 10 31 ed 83 c5 01 <8b> 40 24 85 c0 75 f6 8b 44 24 18 89 04 24 bb 01 00 00 00 31 f6
EIP: [<c0194b0c>] sysfs_follow_link+0xe6/0x254 SS:ESP 0068:f4039ea4
BUG: at lib/kref.c:32 kref_get()
[<c01ec858>] kref_get+0x3d/0x3f
[<c01ebcd6>] kobject_get+0xf/0x13
[<c0194c00>] sysfs_follow_link+0x1da/0x254
[<c0162b12>] generic_readlink+0x27/0x6e
[<c011c434>] timespec_trunc+0x18/0x5d
[<c011ca11>] current_fs_time+0x41/0x50
[<c015f43a>] sys_readlinkat+0x61/0x7a
[<c015f47a>] sys_readlink+0x27/0x2b
[<c01027ee>] sysenter_past_esp+0x5f/0x85
[<c02f0000>] __down_interruptible+0xa2/0x10e
=======================

- As adapters do not get a driver (or what ?), each time you start X, three
new folders are created in /sys/class/i2c-adapter/
For some AGP black magic, the driver is loaded/registered/whatever 2 times
on each X start.

So, after each X start, you get SIX broken dirs in /sys that hang and oops
every app that tries to list i2c devices (like Gnome Sensors Applet, so your
Gnome login hangs forever....). Just ls /sys/class/i2c-adapter/i2c-*/.
It also oopses when removing i2c modules.

No driver should be able to do that to Linux, even if I try lo load a jpeg
of my children renamed to .ko....

--
J.A. Magallon <jamagallon()ono!com> \ Software is like sex:
\ It's better when it's free
Mandriva Linux release 2007.1 (Cooker) for i586
Linux 2.6.20-jam01 (gcc 4.1.2 20070115 (prerelease) (4.1.2-0.20070115.1mdv2007.1)) #1 SMP PREEMPT