On 10/01/2020 19:23, Andrew Lunn wrote:

quoted

If really necessary I could ask the TOS developers to assist, not sure
whether they would oblidge. Their Master branch build bot compiles twice a
day.
Would it just involve setting a kernel debug flag or something more
elaborate?

You could ask them to build a kernel with dynamic debug enabled

https://www.kernel.org/doc/html/latest/admin-guide/dynamic-debug-howto.html

You can then turn on debugging in a flexible way. And it will be
useful for more than just you.

     Andrew

I have put in the request and will see how it goes, if positive I would
probably need a bit of guidance of how to leverage it.

Meantime, assuming for a moment that:

- the issue is not caused by SFP.C (emphasising that I reckon it is
indeed not)
- the is not caused by the module either (which I am not certain of)

, and considering that /sys/kernel/debug/gpio is not mounted on a block
device,

I was wondering whether the I2C bus could potentially get chocked of
sorts and thus preventing the module to propagate the change in tx-fault
signal state in a timely fashion (300 ms) to the kernel, thus being the
actual culprit?