Re: i915 PSR test results and cursor lag

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Thu, Feb 01, 2018 at 05:43:56PM +0000, Andy Lutomirski wrote:
> On Thu, Feb 1, 2018 at 9:40 AM, Andy Lutomirski <luto@xxxxxxxxxx> wrote:
> > Hi-
> >
> > As requested in your blog post, I tested PSR.  I see something like
> > 2.69W with PSR off and 2.17W with PSR on.  Screen blanking,
> > suspend/resume, and the contents of the screen all seem okay.  This is
> > a Dell XPS 13 9350, i.e.:
> >
> > System Information
> >         Manufacturer: Dell Inc.
> >         Product Name: XPS 13 9350
> >
> > EDID is attached.
> >
> > *However*, I do see one unfortunate side effect of turning on PSR.  It
> > seems that, when I move my cursor a little bit after a few seconds of
> > doing nothing, there seems to be a little bit of lag, as if either a
> > few frames are dropped at the beginning of the motion or maybe the
> > entire motion is delayed a bit.  I don't notice a similar delay when
> > typing, so I'm wondering if maybe there's a minor driver bug in which
> > the driver doesn't kick the panel out of PSR quite as quickly when the
> > cursor is updated as it does when the framebuffer is updated.
> >
> 
> I'm also getting occasional messages like:
> 
> [ 2675.574486] [drm:intel_pipe_update_start [i915]] *ERROR* Potential
> atomic update failure on pipe A
> 
> with PSR on.  But there is nowhere near one of these messages per tiny
> lag incident.

That's indeed strange.
I believe that should also be part of PSR + DMC, so could you check if you
see this with psr enabled + dc state disabled?

I wonder if those I915_READ_FW are not waking DMC hence reading 0 in some
registers.

_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx




[Index of Archives]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]
  Powered by Linux