On Wed, 8 Dec 2010 13:33:20 -0500 Andrew Lutomirski <[email protected]> wrote:
> On Wed, Dec 8, 2010 at 1:17 PM, Andrew Lutomirski <[email protected]> wrote: > > On Tue, Dec 7, 2010 at 5:13 PM, Chris Wilson <[email protected]> > > wrote: > >> On Tue, 7 Dec 2010 16:31:24 -0500, Andrew Lutomirski <[email protected]> wrote: > >>> On Tue, Dec 7, 2010 at 4:03 PM, Andrew Lutomirski <[email protected]> wrote: > >>> > Hi all- > >>> > > >>> > Somewhere between Fedora 13 (with 2.6.35, I think) and Fedora 14 + > >>> > 2.6.36.1, i915 started generating exactly 50 interrupts per second > >>> > (suspiciously equal to my refresh rate) when X is running. I have the > >>> > Xorg driver 2.12.0 (specifically > >>> > xorg-x11-drv-intel-2.12.0-6.fc14.1.x86_64). When I switch to a text > >>> > console but leave X running, the interrupts stop. > >>> > > >>> > Any ideas what to look at? > >>> > >>> Quitting compiz fixes it. Suspending compiz also fixes it. > >> > >> So it is the vblank interrupt. The vblank interrupt is get alive for a few > >> seconds after the last use. If it keeps going, then either the system is > >> as idle as you believe or we lost track of the last user and forget to > >> switch off the interrupt. > >> > >> drm.debug=0xf (echo 0xf > /sys/module/drm/parameters/debug) will have the > >> gory details of who/when triggers the vblank interrupt. > >> -Chris > > > > It's the seconds on the clock. That causes activity once per second, > > which looks like this: > > > > [...] > > > > > Maybe that "several seconds" (5, according to the source) timer is way > > too long. Is there any reason that drm_vblank_put doesn't turn off > > interrupts immediately (or, at the latest, on the very next vblank > > interrupt)? After all, preventing deep sleep whenever there is > > display activity every five seconds seems like a waste of power. > > This patch fixes it. It's obviously not ready for prime time, but if > you're OK with the idea I can fix it up and submit it. > > Signed-off-by: Andy Lutomirski <[email protected]> > > Diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c > index 9d3a503..49eca3f 100644 > --- a/drivers/gpu/drm/drm_irq.c > +++ b/drivers/gpu/drm/drm_irq.c > @@ -471,7 +471,7 @@ void drm_vblank_put(struct drm_device *dev, int crtc) > > /* Last user schedules interrupt disable */ > if (atomic_dec_and_test(&dev->vblank_refcount[crtc])) > - mod_timer(&dev->vblank_disable_timer, jiffies + 5*DRM_HZ); > + mod_timer(&dev->vblank_disable_timer, jiffies); > } > EXPORT_SYMBOL(drm_vblank_put); This will just move the problem around a bit; 5s is arguably too long to wait before disabling interrupts, but having a second hand or blinking : in your clock is the real issue here. Why don't you disable that instead? -- Jesse Barnes, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
