On Thu, Jun 06, 2013 at 12:17:26AM +0200, Daniel Vetter wrote: > On some chipset we try to avoid possibly invasive output detection > methods (like load detect which can cause flickering elsewhere) in the > output poll work. Drivers could hence return unknown when a previous > full ->detect call returned a different state. > > This change will generate a hotplug event, forcing userspace to do a > full scan. This in turn updates the connector->status field so that we > will _again_ get a state change when the hotplug work re-runs in 10 > seconds. > > To avoid this ping-pong loop detect this situation and clamp the > connector state to the old value. > > Patch is inspired by a patch from Knut Peterson. Knut's patch > completely ignored connector state changes if either the old or new > status was unknown, which seemed to be a bit too agressive to me. > > References: http://lists.freedesktop.org/archives/dri-devel/2012-August/025975.html > Cc: Knut Petersen <Knut_Petersen@xxxxxxxxxxx> > Cc: Alex Deucher <alexander.deucher@xxxxxxx> > Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx> Also Reviewed-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> I don't think this has any effect for i915, the circumstances where it might we return connector->status rather than Unknown, so we need some input from nouveau/radeon/architect as to our sanity. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
