On Fri, Dec 06, 2013 at 08:29:01PM -0200, Paulo Zanoni wrote: > From: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx> > > Currently, PC8 is enabled at modeset_global_resources, which is called > after intel_modeset_update_state. Due to this, there's a small race > condition on the case where we start enabling PC8, then do a modeset > while PC8 is still being enabled. The racing condition triggers a WARN > because intel_modeset_update_state will mark the CRTC as enabled, then > the thread that's still enabling PC8 might look at the data structure > and think that PC8 is being enabled while a pipe is enabled. Despite > the WARN, this is not really a bug since we'll wait for the > PC8-enabling thread to finish when we call modeset_global_resources. > > The spec says the CRTC cannot be enabled when we disable LCPLL, so we > had a check for crtc->base.enabled. If we change to crtc->active we > will still prevent disabling LCPLL while the CRTC is enabled, and we > will also prevent the WARN above. > > This is a replacement for the previous patch named > "drm/i915: get/put PC8 when we get/put a CRTC" > > Testcase: igt/pm_pc8/modeset-lpsp-stress-no-wait > Signed-off-by: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx> Queued for -next, thanks for the patch. -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
