[Intel-gfx] i915GM+vertical RR+FPS+OpenGL

[SD]

--- On Thu, 5/6/10, SD <sd.domrep at yahoo.com> wrote:

> From: SD <sd.domrep at yahoo.com>
> Subject: Re: [Intel-gfx] i915GM+vertical RR+FPS+OpenGL
> To: "Jesse Barnes" <jbarnes at virtuousgeek.org>
> Date: Thursday, May 6, 2010, 6:38 AM
> 
> 
> --- On Thu, 5/6/10, Jesse Barnes <jbarnes at virtuousgeek.org>
> wrote:
> 
> > From: Jesse Barnes <jbarnes at virtuousgeek.org>
> > Subject: Re: [Intel-gfx] i915GM+vertical
> RR+FPS+OpenGL
> > To: "SD" <sd.domrep at yahoo.com>
> > Cc: intel-gfx at lists.freedesktop.org
> > Date: Thursday, May 6, 2010, 5:56 AM
> > On Wed, 5 May 2010 18:14:47 -0700
> > (PDT)
> > SD <sd.domrep at yahoo.com>
> > wrote:
> > 
> > > Dear All.
> > > 
> > > Sorry to disturb you again.
> > > When I start glxgears on Fedora 13, it tells me
> that
> > application and
> > > suppose to be OpenGL, now synchronized to
> Vertical
> > Refresh Rate
> > > (VRR), which in my case - laptop LCD = 60. And it
> also
> > tells me that
> > > FPS should be ~ the same. Good. No problem with
> it.
> > > 
> > > But when I start it - I got only ~25FPS.
> > > When i start to play a movie in different window,
> then
> > glxgears gives
> > > me really nearly 60 (58,xxx)FPS.
> > > 
> > > Question is why so. If it sync. now to VRR why I
> do
> > not get 60FPS
> > > always? I notice that conpiz as well not really
> smooth
> > and it can be
> > > like that because FPS = 25 and not 60.
> > > 
> > > Can someone explain me that.
> > 
> > If you're on 945, it could be due to what I think is a
> bad
> > pipe setup.
> > On those chips, the vblank interrupt is delayed until
> after
> > a few other
> > things happen, and if we program the
> pipes/planes/plls
> > wrong or don't
> > wait the right amount of time, I think it can get
> stuck and
> > you'll not
> > receive vblank interrupts at all.  If you're lucky,
> > the i915 driver
> > will share an IRQ with some other device, which will
> cause
> > it to get
> > called.  Since the bits are still flipping in hw,
> > we'll emit vblank
> > events, but they won't correspond to when they should
> have
> > occurred or
> > occur at the right frequency.
> > 
> > Jesse
> > 
 
 Thanks.
 I use i915GM video chipset, and only can have something
 like ~58FPS when I start to play video or start to move
 mouse around (quickly enough). In other cases I have 25.
 This also happens in game (quake) normally I have 20-25,
 but if things starts to move around the FPS goes up as
 well.
 Is it a bug, and do I have to fill it up on bugzilla?
 
 Thanks.