Hello,
it would be nice if you can find what's going on. Here is a detailed
description of the problem (kernel 2.4.24):
While modprobing the module the following error occurs (modprobe
i2c-pcf-epp):
On the console:
/lib/modules/2.4.20/kernel/drivers/i2c/i2c-pcf-epp.o: init_module: No such
device or address
Hint: insmod errors can be caused by incorrect module parameters, including
invalid IO or IRQ parameters
/lib/modules/2.4.20/kernel/drivers/i2c/i2c-pcf-epp.o: insmod
/lib/modules/2.4.20/kernel/drivers/i2c/i2c-pcf-epp.o failed
/lib/modules/2.4.20/kernel/drivers/i2c/i2c-pcf-epp.o: insmod i2c-pcf-epp
failed
Here is the content of dmesg:
i2c-core.o: i2c core module version 2.8.2 (20031211)
i2c-pcf-epp.o: i2c pcf8584-epp adapter module version 2.8.2 (20031211)
i2c_pcf_add_bus caused an error: -6
Before loading the module (less /proc/interrupts):
CPU0
0: 34934 XT-PIC timer
1: 112 XT-PIC keyboard
2: 0 XT-PIC cascade
10: 14 XT-PIC ide1
11: 40 XT-PIC usb-uhci, eth0
12: 20 XT-PIC PS/2 Mouse
14: 3193 XT-PIC ide0
NMI: 0
ERR: 0
After (there is a segfault)
Unable to handle kernel paging request at virtual address cf86666b
*pde = 0ed3e067
*pte = 00000000
Oops: 0000
CPU: 0
EIP: 0010:[<c02308a0>] Not tainted
EFLAGS: 00010297
eax: cf86666b ebx: cd6770b2 ecx: cf86666b edx: fffffffe
esi: cd9a9f1c edi: ffffffff ebp: cf86666b esp: cd9a9ec4
ds: 0018 es: 0018 ss: 0018
Process less (pid: 1319, stackpage=cd9a9000)
Stack: cd6770b0 cdc5aa00 00000007 000000e0 cdc5aa00 00000007 ffffffff
00000000
ffffffff c0230aa5 cd6770b0 32988f50 c0234f37 cd9a9f18 c0230abd
cd6770b0
c0234f34 cd9a9f18 c01095d2 cd6770b0 c0234f34 cf86666b cd6770a1
c0234f2e
Call Trace: [<c0230aa5>] [<c0230abd>] [<c01095d2>] [<c0148c46>]
[<c0146cfd>]
[<c012cb2e>] [<c01084a3>]
Code: 80 38 00 74 07 40 4a 83 fa ff 75 f4 29 c8 89 44 24 10 8b 44
Segmentation fault
The available bios options are as follow (related to the parallel port):
Onboard parallel port : [3BC/IRQ7] or [378/IRQ7] or [278/IRQ5] (choosen
[378/IRQ7])
Onboard parallel mode : [EPP] or [ECP] or [ECP/EPP] (choosen [EPP])
EPP type: [EPP1.7] or [EPP1.9] (choosen [EPP1.9])
IRQ-7 assigned to [Legacy ISA] or [PCI/ISA PnP] (choosen [PCI/ISA PnP])
Which configuration should I use ?
>Great. Couldn't you do the same with more simple parallel-ports
>adapters, such as i2c-philips-par, i2c-elv or i2c-velleman? These have
>been ported to Linux 2.6 already, and are supported by my unified driver
>too, while i2c-pport hasn't been ported and isn't part of the unified
>driver.
Since we have developped our own PC104 motherboard we wanted to integrate
the i2c circuit on it. I couldn't find the elv and velleman schematics.
Furthermore, I was concerning about the performances: hoping that the use of
the PCF8584 will provide better performance. (less cpu load, interrupt
driven for byte reading, etc.)
>Actually I wonder if I will port and/or integrate the i2c-pport logic in
>Linux 2.6, because in most cases, the additional complexity shouldn't be
>required. But if you really need it, I'll think of it.
i2c-pport was very convenient for testing. It took less than an hour for
wiring the cables, loading the module and detecting the slave with
i2cdetect. I might not be the only one who needs it.
Thanks for all!
~Pierre
PS : btw, here is the robot I'm working on
http://asl.epfl.ch/index.html?content=research/systems/Solero/solero.php
-----Original Message-----
From: Jean Delvare [mailto:khali at linux-fr.org]
Sent: Tuesday, January 27, 2004 10:01 PM
To: pierre.lamon at epfl.ch
Cc: LM Sensors
Subject: Re: Follow up for Ticket 1538
> thanks a lot for your answer. I've finally choosen not to use the
> PCF8584 for interfacing the i2c bus because I was not able to modprobe
> it whatever the kernel or the i2c-x version (I've been trying for
> around 3 days). However, I'm still interested to know if it has been
> tested and if anybody uses it successfully.
I'm surprised you couldn't get it to work. As far as I know, the driver
is precisely made for people who build a board according to Simon Vogl's
schematics. If you provide details about the failures, we might try to
help.
> Finally I'm using direct parallel port access and everything works
> fine with the i2c-pport driver :-)
Great. Couldn't you do the same with more simple parallel-ports
adapters, such as i2c-philips-par, i2c-elv or i2c-velleman? These have
been ported to Linux 2.6 already, and are supported by my unified driver
too, while i2c-pport hasn't been ported and isn't part of the unified
driver.
Actually I wonder if I will port and/or integrate the i2c-pport logic in
Linux 2.6, because in most cases, the additional complexity shouldn't be
required. But if you really need it, I'll think of it.
--
Jean Delvare
http://www.ensicaen.ismra.fr/~delvare/
