On Wed, Sep 30, 2015 at 07:21:34PM +0300, ville.syrjala at linux.intel.com wrote: > From: Ville Syrjälä <ville.syrjala at linux.intel.com> > > If we couldn't get a high precisions vblank timestamp, we currently > store a zeroed timestamp instead and assume the next vblank irq to > get us something better. This makes sense when trying to update the > timestamp from eg. vblank enable. But if we do this from the vblank > irq we will never get a vblank timestamp unless we high precision > timestamps are available and succeeded. This break weston for instance > on drivers lacking high precision timestamps. > > To fix this, zero the timestamp only when not called from vbl irq. > When called from the irq, we still want the timestamp, even if not > perfect. > > This fixes a regression from > 4dfd64862ff852df drm: Use vblank timestamps to guesstimate how many vblanks > were missed > > Cc: Mario Kleiner <mario.kleiner.de at gmail.com> > Cc: Thierry Reding <thierry.reding at gmail.com> > Reported-by: Thierry Reding <thierry.reding at gmail.com> > Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com> > --- > drivers/gpu/drm/drm_irq.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-)
Applied on top of next-20151001 and the weston problem I was seeing is gone, so: Tested-by: Thierry Reding <treding at nvidia.com> I think it might be worth considering squashing this into the offending commit to avoid breaking bisectibility. Thierry -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: not available URL: <http://lists.freedesktop.org/archives/dri-devel/attachments/20151001/09e97c7b/attachment.sig>
