On Tue, Sep 22, 2015 at 01:15:01PM +0200, Maarten Lankhorst wrote: > Op 22-09-15 om 11:10 schreef Daniel Vetter: > > On Mon, Sep 14, 2015 at 10:43:52PM +0300, ville.syrjala@xxxxxxxxxxxxxxx wrote: > >> From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > >> > >> The vblank timestamp ringbuffer only has two entries, so if the > >> vblank->count is incremented by an even number readers may end up seeing > >> the new vblank timestamp alongside the old vblank counter value. > >> > >> Fix the problem by storing the vblank counter in a ringbuffer as well, > >> and always increment the ringbuffer "slot" by one when storing a new > >> timestamp+counter pair. > >> > >> Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > Imo if we bother with this we might as well just switch over to using > > full-blown seqlocks. They internally use a two-stage update which means > > race-free even with just one copy of the data we protect. Also more > > standardized to boot. > > > > Series looks good otherwise, I'll wait for Maarten to r-b it and then pull > > it in. > > > R-b for 1-10. Merged to drm-misc, thanks. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
