[Intel-gfx] [PATCH i-g-t] RFC: split PM workarounds into separate lib

Daniel Vetter daniel at ffwll.ch
Fri Dec 11 09:03:30 PST 2015

On Thu, Dec 10, 2015 at 06:01:28PM +0200, David Weinehall wrote:
> On Tue, Dec 08, 2015 at 03:42:27PM +0200, Ville Syrjälä wrote:
> > On Tue, Dec 08, 2015 at 10:50:39AM +0200, David Weinehall wrote:
> > > Since the defaults for some external power management related settings
> > > prevents us from testing our power management functionality properly,
> > > we have to work around it. Currently this is done from the individual
> > > test cases, but this is sub-optimal.  This patch moves the PM-related
> > > workarounds into a separate library, and adds some code to restore the
> > > previous settings for the SATA link power management while at it.
> > 
> > Why is it called "workarounds"? That gives me the impression we're
> > working around something that's supposed to work but doesn't. That's not
> > the case here.
> Workarounds was because we are working around "imperfect" settings
> in other components. At least to me power management should be enabled
> out of the box, not something that requires admin-level workarounds.
> Since we're not in control of said defaults, we have to modify the
> settings when we run our tests, hence workarounds.

Fully agreed that power tuning should be applied by default, but that's a
loooooong process to convince all the other kernel maintainers. And we
need to get our own house in order first too, but that's in progress.

> That said, as I've replied to a later post, igt_pm is fine by me.

One more: Please namespace all the library functions you're adding and
exporting to tests with igt_pm_. Static/internal functions can still be
named however you feel like.
Daniel Vetter
Software Engineer, Intel Corporation

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