[Arm-dev] No access to HAT i2c EEPROM

Mon Jun 15 23:07:25 UTC 2020
Stephan GUILLOUX <stephan.guilloux at free.fr>

Some progress.

I reinstalled a SD and updated manually all the kernel RPMS that I can find.

Only last kernel has this change (5.4.28 is still ok).



On 15-Jun-20 22:59, Stephan GUILLOUX wrote:

> Hello all,
>
>
> Maybe some will be able to help a bit.
>
> I'm running 2 Raspberries 3B+, with the same old CentOS image, freshly 
> prepared.
>
> Both run raspberrypi2-kernel 4.19.xx
>
> Both Raspberry have a hat, with a valid EEPROM.
>
>
> On both, the application I'm in charge of, has R/W access to
>
> /sys/class/i2c-adapter/i2c-3/3-0050/eeprom
>
>
> On one Raspberry, I update the kernel and only the kernel (yum update 
> raspberrypi2-kernel) and I come to 5.4.42.
>
> After reboot, the whole content of /sys/class has changed, regarding I2C.
>
> 4.19.94:
>
> [root at Raspberry-DD7BD7 OLD ~]$ ls -al /sys/bus/i2c/devices/
> total 0
> drwxr-xr-x. 2 root root 0 Jan  1  1970 .
> drwxr-xr-x. 4 root root 0 Jan  1  1970 ..
> lrwxrwxrwx. 1 root root 0 Jan  1  1970 3-0050 -> 
> ../../../devices/platform/ffffffff.i2c/i2c-3/3-0050
> lrwxrwxrwx. 1 root root 0 Jan  1  1970 i2c-3 -> 
> ../../../devices/platform/ffffffff.i2c/i2c-3
> [root at Raspberry-DD7BD7 OLD ~]$ ls -al /sys/bus/i2c/devices/3-0050/eeprom
>
> 5.4.42:
>
> [root at CertifBox-8AC500 OLD ~]$ ls -al /sys/class/i2c-adapter/
> total 0
> drwxr-xr-x.  2 root root 0 Jan  1  1970 .
> drwxr-xr-x. 54 root root 0 Jan  1  1970 ..
> lrwxrwxrwx.  1 root root 0 Jun 15 22:53 i2c-11 -> 
> ../../devices/platform/ffffffff.i2c/i2c-11
> [root at CertifBox-8AC500 OLD ~]$
>
>
> Any idea where I can find this EEPROM file ?
>
> A module option, maybe ?
>
>
> Regards,
>
> Stephan.
>
>
>
>
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