How to see the content of my device's EEPROM?

How to see the content of my device's EEPROM?

[Alexandre-Xavier Labonté-Lamoureux]

Hello everyone,

On the kernel version 4.3.3, when I do dmesg to see the content of the
EEPROM of the device that I just connected, I don't see it.

I only see this: https://justpaste.it/qchd

On older kernel versions like 3.10, I had what I wanted:
https://justpaste.it/qchh

i2c eeprom 00: 1a eb 67 95 1a eb 51 50 50 00 20 03 82 34 6a 04
i2c eeprom 10: 6e 14 27 57 06 02 00 00 00 00 00 00 00 00 00 00
i2c eeprom 20: 02 00 01 00 f0 10 01 00 b8 00 00 00 5b 00 00 00
i2c eeprom 30: 00 00 20 40 20 80 02 20 01 01 00 00 00 00 00 00
i2c eeprom 40: 00 00 00 00 00 00 00 00 00 00 00 00 00 c4 00 00
i2c eeprom 50: 00 a2 00 87 81 00 00 00 00 00 00 00 00 00 00 00
i2c eeprom 60: 00 00 00 00 00 00 00 00 00 00 04 03 30 00 14 03
i2c eeprom 70: 49 00 4f 00 4e 00 20 00 41 00 75 00 64 00 69 00
i2c eeprom 80: 6f 00 34 03 49 00 4f 00 4e 00 20 00 41 00 75 00
i2c eeprom 90: 64 00 69 00 6f 00 20 00 55 00 53 00 42 00 20 00
i2c eeprom a0: 32 00 38 00 36 00 31 00 20 00 44 00 65 00 76 00
i2c eeprom b0: 69 00 63 00 65 00 00 00 00 00 00 00 00 00 00 00
i2c eeprom c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
i2c eeprom d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
i2c eeprom f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Why do newer kernels print less information to dmesg? How do I do if I want
to see the content of my EEPROM on kernel v4.3.3 ?

Thanks in advance,
Alexandre-Xavier

Re: How to see the content of my device's EEPROM?

[Olli Salonen]

Hi,

Load the module with i2c_debug on:

From: em28xx-i2c.c:

693         if (i2c_debug) {
694                 /* Display eeprom content */
695                 print_hex_dump(KERN_INFO, "eeprom ", DUMP_PREFIX_OFFSET,
696                                16, 1, data, len, true);
697
698                 if (dev->eeprom_addrwidth_16bit)
699                         em28xx_info("eeprom %06x: ... (skipped)\n", 256);
700         }

modprobe em28xx i2c_debug=1 should do it.

Cheers,
-olli

On 8 March 2016 at 05:03, Alexandre-Xavier Labonté-Lamoureux
<alexandrexavier@live.ca> wrote:
> Hello everyone,
>
> On the kernel version 4.3.3, when I do dmesg to see the content of the
> EEPROM of the device that I just connected, I don't see it.
>
> I only see this: https://justpaste.it/qchd
>
> On older kernel versions like 3.10, I had what I wanted:
> https://justpaste.it/qchh
>
> i2c eeprom 00: 1a eb 67 95 1a eb 51 50 50 00 20 03 82 34 6a 04
> i2c eeprom 10: 6e 14 27 57 06 02 00 00 00 00 00 00 00 00 00 00
> i2c eeprom 20: 02 00 01 00 f0 10 01 00 b8 00 00 00 5b 00 00 00
> i2c eeprom 30: 00 00 20 40 20 80 02 20 01 01 00 00 00 00 00 00
> i2c eeprom 40: 00 00 00 00 00 00 00 00 00 00 00 00 00 c4 00 00
> i2c eeprom 50: 00 a2 00 87 81 00 00 00 00 00 00 00 00 00 00 00
> i2c eeprom 60: 00 00 00 00 00 00 00 00 00 00 04 03 30 00 14 03
> i2c eeprom 70: 49 00 4f 00 4e 00 20 00 41 00 75 00 64 00 69 00
> i2c eeprom 80: 6f 00 34 03 49 00 4f 00 4e 00 20 00 41 00 75 00
> i2c eeprom 90: 64 00 69 00 6f 00 20 00 55 00 53 00 42 00 20 00
> i2c eeprom a0: 32 00 38 00 36 00 31 00 20 00 44 00 65 00 76 00
> i2c eeprom b0: 69 00 63 00 65 00 00 00 00 00 00 00 00 00 00 00
> i2c eeprom c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> i2c eeprom d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> i2c eeprom f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>
> Why do newer kernels print less information to dmesg? How do I do if I want
> to see the content of my EEPROM on kernel v4.3.3 ?
>
> Thanks in advance,
> Alexandre-Xavier