On Fri, May 25, 2018 at 06:19:17PM +0300, Jani Nikula wrote: > On Fri, 25 May 2018, Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> wrote: > > On Thu, May 24, 2018 at 10:19:02PM +0100, Chris Wilson wrote: > >> Quoting Ville Syrjala (2018-05-24 20:04:05) > >> > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > >> > > >> > My ILK seems to generate a spurious PCH underrun with most interlaced > >> > HDMI modes. Add a second vblank wait to avoid it. > >> > >> Fwiw, a second vblank because of interlacing is very believable. > > /me .oO( could we wait for the 2nd vblank based on interlace? ) We certainly could. However as explained below we have seen some similar looking underruns in CI with progressive DP as well, and so I chose to try the shotgun approach in the hopes of hitting a few more barn doors. > > >> > >> > We have seen some spurious PCH underruns still in CI as well, some > >> > of which seem to be progressive DP. The logs also point towards some > >> > spurious underrins with progressive HDMI on SNB. While I don't have > >> > a solid explanation for those let's try to kill all the birds with one > >> > stone and always do the double wait. > >> > > >> > Buzilla: https://bugs.freedesktop.org/show_bug.cgi?id=106387 > >> > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > >> Acked-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>a > > > > Thanks. Pushed to dinq. > > > >> > >> No point waiting for a vblank worker? ;) > > > > That might take a while. Also I'm not sure we'd want to use it here > > because we'd probably want underrun reporting to be active by the > > time we enable the planes. So we'd either have to enable planes from > > the worker as well, or we'd just sample the vblank counter at the > > end of crtc_enable and wait for n+2 just before we start to enable the > > planes. Not sure if that latter approach would gain us any practical > > parallelism though. > > -- > Jani Nikula, Intel Open Source Graphics Center -- Ville Syrjälä Intel _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
