[Intel-gfx] [PATCH 03/10] drm/i915: Expose engine properties via sysfs

[Chris Wilson]

Quoting Tvrtko Ursulin (2019-10-11 09:44:16)
> 
> On 10/10/2019 08:14, Chris Wilson wrote:
> > Preliminary stub to add engines underneath /sys/class/drm/cardN/, so
> > that we can expose properties on each engine to the sysadmin.
> > 
> > To start with we have basic analogues of the i915_query ioctl so that we
> > can pretty print engine discovery from the shell, and flesh out the
> > directory structure. Later we will add writeable sysadmin properties such
> > as per-engine timeout controls.
> > 
> > An example tree of the engine properties on Braswell:
> >      /sys/class/drm/card0
> >      └── engine
> >          ├── bcs0
> >          │   ├── class
> >          │   ├── heartbeat_interval_ms
> 
> Not present in this patch.

I did say an example tree, not this tree :)

> >          │   ├── instance
> >          │   ├── mmio_base
> 
> I vote for putting mmio_base in a followup patch.

Darn your eagle eyes ;)

> 
> And how about we add capabilities in the first patch? So we get another 
> way of engine discovery. Ideally with mapping of bits to user friendly 
> strings.

Right, I was about to ask if we should do a /proc/cpuinfo style
capabilities. Do we need both? Or just stick to the more human readable
output for sysfs?
-Chris