[Intel-gfx] DC6 already programmed to be disabled

[Sagar Arun Kamble]

The warning faced by Chandra has to corrected. This warning is not
related to firmware load. 

Issue is -> During boot DC5/6 will be already disabled and hence While
enabling PW2 for the first time the check to see if DC5/6 is already
disabled does not make sense.

So condition should be

WARN(!(I915_READ(DC_STATE_EN) & DC_STATE_EN_UPTO_DC6) && pg2_enabled),
	"DC6 already programmed to be disabled.\n");


On Tue, 2015-05-19 at 10:18 +0200, Daniel Vetter wrote:
> On Tue, May 19, 2015 at 04:53:16AM +0000, Kamath, Sunil wrote:
> > Sure Damien. We will come back with solution for the same. 
> 
> Please check out my reply to Animesh' patch in
> 
> https://tango.freedesktop.org/patch/49084/
> 
> I think this is the proper fix and the design much more in-line with other
> parts of i915.
> -Daniel
> 
> > 
> > - Sunil
> > 
> > >-----Original Message-----
> > >From: Lespiau, Damien 
> > >Sent: Monday, May 18, 2015 4:14 PM
> > >To: Daniel Vetter
> > >Cc: Konduru, Chandra; intel-gfx at lists.freedesktop.org; Shah, Suketu J; Kamath, Sunil; Manna, Animesh
> > >Subject: Re: [Intel-gfx] DC6 already programmed to be disabled
> > >
> > >On Mon, May 18, 2015 at 10:38:03AM +0200, Daniel Vetter wrote:
> > >> On Fri, May 15, 2015 at 11:22:27PM +0000, Konduru, Chandra wrote:
> > >> > Hi,
> > >> > I have been seeing below warning on skylake system on which dmc fw isn't placed.
> > >> > Is below warning expected? If so what is it conveying?
> > >> 
> > >> Seems to be another fallout from the current design of how we prevent
> > >> dc5/6 when the firmware is not (yet) loaded. I've detailed how this 
> > >> should be fixed. We need to prevent the rpm code from ever trying to 
> > >> shut down that specific power well instead of just not obeying the 
> > >> request. Not obeying the request means the rpm code is out of sync 
> > >> with reality, leading to WARN_ON fun like the one you've hit here.
> > >
> > >Hey all,
> > >
> > >Would anyone of you (Sunil, Animesh, Suketu) have time to fix this? (the warning when DMC firmware isn't there). We should be able to work when failing to load the DMC firmware.
> > >
> > >What Daniel says is not quite accurate, bear in mind we still can shut down all power wells and do PC10 with screens off when the DMC isn't loaded. We could also decide to disable run-time PM entirely when the >DMC firmware isn't there. That's something that can be fixed later on though, right now the most immediate issue is not to dump lots of warnings when failing to load the firmware.
> > >
> > >By default I'll fix it, I have this on my TODO list, it's quite low though.
> > >
> > >Thanks,
> > >
> > >--
> > >Damien
>