Re: [PATCH v3 0/5] SFH: Add Support for AMD Sensor Fusion Hub

From: Jiri Kosina
Date: Fri Feb 21 2020 - 07:47:55 EST


On Wed, 19 Feb 2020, Shah, Nehal-bakulchandra wrote:

> > 2 problems here:
> > - patch 3/5 references this debugfs interface which is only added in 4/5.
> > - you are creating a new sysfs set of file for debug purpose only, but
> > as soon as we start shipping those, some other people will find it
> > more convenient to use that directly instead or IIO, and you won't be
> > able to change anything there.
> >
> > So I would strongly advocate against having this debugfs, and suggest you to:
> > - either keep this debugfs as a downstream patch
> > - either play with eBPF or kprobes to retrieve the same information
> > without changing the kernel.
> >
> > For reference, I recently tried to replicate the hidraw functionality
> > with eBPF[0] without changing the kernel code, and it was working.
> > Well, there was no filtering on the source of the HID event, but
> > still, I got the same data directly from the kernel just by adding
> > instrumentation in a couple of functions.

Wow. Complete eBPF supremacy is really coming shortly apparently :)

> If Jiri is Ok, then we will push the next patch as per suggestion here
> i.e. taking out debugfs.

I agree with that. Thanks,

--
Jiri Kosina
SUSE Labs