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

Andi Shyti
2020-02-08T17:41:31Z

> > > > > > 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)

my symlinks suggestions was a mix of the above and it would be:

1. add symlinks (or redundant files with warning) and mark the
interfaces as deprecated.
2. in 5.9 remove the symlinks (or redundant files, I like the
idea of warning userspace).
3. expect anyway complaints :-P

Let's give it a few days, perhaps after the weekend someone might
have an opinion or better recommendation.

Andi