On Fri, Feb 27, 2015 at 03:03:22PM +0200, Ville Syrjälä wrote: > On Wed, Feb 25, 2015 at 10:31:13PM +0100, Daniel Vetter wrote: > > On Wed, Feb 18, 2015 at 02:28:16PM +0000, John Harrison wrote: > > > On 13/02/2015 17:03, Chris Wilson wrote: > > > >On Fri, Feb 13, 2015 at 04:58:24PM +0000, John Harrison wrote: > > > >>On 13/02/2015 12:19, Chris Wilson wrote: > > > >>>On Fri, Feb 13, 2015 at 11:48:56AM +0000, John.C.Harrison@xxxxxxxxx wrote: > > > >>>>From: John Harrison <John.C.Harrison@xxxxxxxxx> > > > >>>> > > > >>>>Updated ironlake_enable_rc6() to do explicit request creation and submission. > > > >>>If you merged the context here with the common context switching code, > > > >>>we don't even need to touch the ring here. > > > >>>-Chris > > > >>> > > > >>It would certainly be preferable to not have any ring commands > > > >>written from deep within the power management code. However, I > > > >>didn't want to change anything I didn't really need to, especially > > > >>in code that I'm not at all sure about. Plus I don't have an > > > >>ironlake to test any significant change on. > > > >I did and tested extensively. > > > >-Chris > > > > > > Do you have a patch that just does the move of this from PM code to context > > > switch code? Something that I can drop into this series would be great. If > > > not, exactly where about in the context switch code should it go? Should it > > > be in the start of day initialisation, in the per context intialisation, > > > every context switch, only the first switch after a resume, ...? > > > > > > Tracing back to where/when this code is currently executed seems to be quite > > > complicated. The _enable_rc6() function is called during ring reset but only > > > for Gen6+ because Ironlake is broken according to the comment. It is also > > > called by a system power management callback but it is unclear when that > > > would occur. Finally, it is also called from the display code in > > > intel_modeset_init_hw(). > > > > ilk rc6 is disabled by default because it crashes machines hard and > > doesn't seem to be all that useful really. Compared to gen6+ rc6 which has > > a massive impact on idle power consumption, more with each generation. > > > > I've also never heard of anyone managing to make this work reliably. We > > could also just rip the entire code out I think, at least I wouldn't be > > surprised if it has bitrot completely by now. > > I was running with it when Ben had those ILK context+rc6 patches flying > around. But I admit that was some time ago. Iirc we've enabled it for a bit with those, it fell to pieces too. And it seems to be rare enough that testing on a developers machine doesn't cut it (tried myself to enable it a few times and had to revert again). -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
