[linux-dvb] KNC1 DVB-C as second card -> tda10021_attach segfaults

[wolfgang@leila.ping.de]

Hi,
I am finally trying to get the KNC1 DVB-C w/ av_in running in my "analyzer" 
machine as the second card (first is an old Hauppauge DVB-S budget card, 
Model 541 i think). 
The first problem was that this card has a new ID:
0000:01:07.0 Multimedia controller: Philips Semiconductors SAA7146 (rev 01)
      Subsystem: KNC One: Unknown device 0021
(I do not know if it really is a new revision or just the difference because 
this card has the analog video input.) 
After adding the 0x21 to the PCI device list, the driver crashes when 
calling tda10021_readreg(state, 0x1a) in tda10021_attach. 
I could not yet figure out what might be wrong with the I2C device, the 
read_pwm() call immediately before this works. 
Does anybody have an idea what is going wrong here? 
Thanks,
Wolfgang 
see below for the messages (the "registering i2c adapter" was added by me): 
saa7146: register extension 'budget dvb /w video in'.
ACPI: PCI interrupt 0000:01:07.0[A] -> GSI 5 (level, low) -> IRQ 5
saa7146: found saa7146 @ mem c8b68400 (revision 1, irq 5) (0x1894,0x0021).
DVB: registering new adapter (KNC1 DVB-C).
registering i2c adapter
registered i2c adapter
adapter failed MAC signature check
encoded MAC from EEPROM was 
ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff:ff
saa7146_vv: saa7146 (1): registered device video0 [v4l2]
KNC1-1: MAC addr = 00:09:d6:6d:11:48
Unable to handle kernel NULL pointer dereference at virtual address 00000000
printing eip:
c8b58198
*pde = 00000000
Oops: 0000 [#1]
PREEMPT
Modules linked in: budget_av tda10021 md5 ipv6 ehci_hcd usbcore tuner 
tvaudio bttv i2c_algo_bit btcx_risc saa7146_vv video_buf v4l1_compat 
v4l2_common videodev firmware_class tda1004x budget l64781 ves1820 
budget_core saa7146 ttpci_eeprom stv0299 tda8083 ves1x93 dvb_core crc32 
i2c_core snd_intel8x0 snd_ac97_codec snd_pcm snd_timer snd soundcore 
snd_page_alloc shpchp pci_hotplug hw_random intel_agp evdev 3c59x agpgart 
ide_cd cdrom rtc unix
CPU:    0
EIP:    0060:[<c8b58198>]    Not tainted VLI
EFLAGS: 00010282   (2.6.10-dvbcvs-02022005)
EIP is at tda10021_readreg+0xb8/0xe0 [tda10021]
eax: 00000000   ebx: c71cca00   ecx: c8b58b4a   edx: ffffff87
esi: c8b595b4   edi: c71ccaf8   ebp: 00000048   esp: c6383dac
ds: 007b   es: 007b   ss: 0068
Process modprobe (pid: 6231, threadinfo=c6382000 task=c74a2580)
Stack: c12ff888 c6383de0 c8b58b4a ffffff87 1a0038a0 0000000c 00000001 
c6383dbf
     0001000c c6380001 c6383dbe 00000003 c899ae17 0000000c 00000001 
c6383dbf
     0001000c c6380001 c6383dbe c6383e04 00000002 c71cca00 c8b58b18 
c71cca00
Call Trace:
[<c899ae17>] i2c_transfer+0x37/0x60 [i2c_core]
[<c8b58b18>] tda10021_attach+0x78/0x98 [tda10021]
[<c8b5f280>] frontend_init+0x120/0x170 [budget_av]
[<c0118997>] printk+0x17/0x20
[<c8b5f698>] budget_av_attach+0x228/0x2f0 [budget_av]
[<c89ab848>] saa7146_init_one+0x328/0x600 [saa7146]
[<c01d0e72>] pci_device_probe_static+0x52/0x70
[<c01d0ecc>] __pci_device_probe+0x3c/0x50
[<c01d0f0c>] pci_device_probe+0x2c/0x50
[<c02121ef>] driver_probe_device+0x2f/0x80
[<c021233c>] driver_attach+0x5c/0xa0
[<c021288d>] bus_add_driver+0x9d/0xd0
[<c0212eaf>] driver_register+0x2f/0x40
[<c01d1194>] pci_register_driver+0x64/0x90
[<c89abd5b>] saa7146_register_extension+0x9b/0xe0 [saa7146]
[<c8b4d00f>] budget_av_init+0xf/0x11 [budget_av]
[<c01308b2>] sys_init_module+0x162/0x210
[<c01030df>] syscall_call+0x7/0xb
Code: 08 8d 44 24 34 89 44 24 04 8b 03 89 04 24 e8 60 2c e4 ff 83 f8 02 74 
25 89 44 24 0c b9 4a 8b b5 c8 89 4c 24 08 8b 83 00 01 00 00 <8b> 00 c7 04 24 
e0 8b b5 c8 89 44 24 04 e8 d6 07 5c f7 0f b6 44 
(sorry for this ugly copy&paste)