Re: [igt-dev] [PATCH i-g-t 07/10] lib/psr: Drop support to old kernels without new PSR debugfs interface

Petri Latvala
2019-01-17T09:50:54Z

On Thu, Jan 17, 2019 at 02:07:27AM +0000, Souza, Jose wrote:
> On Tue, 2019-01-15 at 21:21 -0800, Dhinakaran Pandiyan wrote:
> > On Fri, 2019-01-11 at 17:46 -0800, José Roberto de Souza wrote:
> > > The nexts patches will add PSR2 tests and for that we need the new
> > > PSR debugfs interface that was released in kernel 4.20 so it will
> > > not
> > > break for any updated system and we can drop support to the old
> > > debugsfs and the support to kernels without even a debugfs
> > > interface.
> >
> > Can't we have psr_set(mode == PSR_MODE_2) skip if the kernel does not
> > support the new interface?
>
> We could but why keep supporting old kernels? My experience of running
> a newer IGT over a old kernel or on the contrary was always
> problematic.

Any problematic experiences you might have encountered should be filed
as bugs. We do support old kernels (to a length) and shouldn't
knowingly break support for them without an informed decision.

--
Petri Latvala