[Intel-gfx] [PATCH] drm/i915/gt: make a gt sysfs group and move power management files

[Chris Wilson]

Quoting Andi Shyti (2020-02-08 17:01:53)
> Hi Chris,
> 
> > > > > The GT has its own properties and in sysfs they should be grouped
> > > > > in the 'gt/' directory.
> > > > > 
> > > > > Create the 'gt/' directory in sysfs and move the power management
> > > > > related files.
> > > > 
> > > > As shown by BAT, we have a conundrum; do we have to preserve the old
> > > > names forevermore? Or do we just userspace that they have to adapt?
> > > 
> > > With this, I guess you are suggesting to change igt accordingly,
> > > because I'm pretty sure this interface is subject to change,
> > > sooner or later.
> > 
> > Right; but what about powertop? And the bajillion wikis?
> 
> mmhhh... right!
> 
> > Just feels clumsy, so I'd like to spend a moment to see if we can think
> > of any options before dropping them. No matter how silly, if userspace
> > breaks, it's a regression :(
> > 
> > Maybe we could do something like keep the old ones and put a deprecation
> > warning in?
> 
> how about linking and declare the old interface obsolete?

Is a possibility, but I'm not keen on having more and more dangling
symlinks.

1. Do nothing; have redundant files.
2. Remove them, expect complaints.
3. Mark them as deprecated, remove in 5.9?
4. Symlinks forevermore (not clear if we can symlink and emit a warning)
5. Profit?
-Chris