[i2c] I2C probe 10bit address

Salvatore Benedetto emitrax at gmail.com
Tue Nov 14 00:07:32 CET 2006

Hi all,

I'm trying to get a WinTV USB (Hauppauge!) card working on a embedded system
(FOX board). This peripheral
is fully supported under linux, thanks to the usbvision driver. This module
though, needs the I2C Linux
subsystem to work, which originally was not available on my target system.
So, in order to compile the module, I had to add the I2C subsystem to the
kernel of the
devboard. Compilation and loading of the modules went fine. However,
everytime the I2C core tries to probe
the i2c address it gives me this error:

[ 4319.880000] i2c_adapter i2c-0: Invalid probe address 0xffff
[ 4394.050000] i2c_adapter i2c-0: Invalid probe address 0x00
[ 4666.090000] i2c_adapter i2c-0: Invalid probe address 0xffff
[ 4722.730000] i2c_adapter i2c-0: Invalid probe address 0xffff

So I looked in the source of the core and I found this comment

/* ----------------------------------------------------
 * the i2c address scanning function
 * Will not work for 10-bit addresses!
 * ----------------------------------------------------
static int i2c_probe_address(struct i2c_adapter *adapter, int addr, int
                             int (*found_proc) (struct i2c_adapter *, int,

Now, for what I have studied about I2C, addresses can be either of 7 or 10
bits address, right? I guess the processor
of this board uses 10bits address, because I don't see any other explanation
to that message.

So I'm wondering if is there any patch available to make the
i2c_probe_address function working with 10bit addresses? Or is there any
workaround I can use? I looked on google for some howto that would explain
how to solve this problem , but I didn't find much.

I hope my question is not off topic on this mailing list.

Thanks in advance

Salvatore Benedetto (a.k.a. emitrax)
Student of Computer Engineering and Telecommunications
University of Messina (Italy)
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