[PATCH 3/3] drm/radeon/kms: implement timestamp userspace query

[Michel Dänzer]

On Die, 2012-08-14 at 10:39 -0400, Jerome Glisse wrote: 
> On Tue, Aug 14, 2012 at 10:36 AM, Michel Dänzer <michel at daenzer.net> wrote:
> > On Don, 2012-08-09 at 10:57 -0400, Jerome Glisse wrote:
> >> On Thu, Aug 9, 2012 at 10:34 AM, Marek Olšák <maraeo at gmail.com> wrote:
> >> >
> >> > diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
> >> > index 637280f..be0e320 100644
> >> > --- a/drivers/gpu/drm/radeon/r600.c
> >> > +++ b/drivers/gpu/drm/radeon/r600.c
> >> > @@ -3789,3 +3789,15 @@ static void r600_pcie_gen2_enable(struct radeon_device *rdev)
> >> >                 WREG32_PCIE_P(PCIE_LC_LINK_WIDTH_CNTL, link_width_cntl);
> >> >         }
> >> >  }
> >> > +
> >> > +uint64_t r600_get_gpu_clock(struct radeon_device *rdev)
> >> > +{
> >> > +       uint64_t clock;
> >> > +
> >> > +       mutex_lock(&rdev->gpu_clock_mutex);
> >> > +       WREG32(RLC_CAPTURE_GPU_CLOCK_COUNT, 1);
> >> > +       clock = (uint64_t)RREG32(RLC_GPU_CLOCK_COUNT_LSB) |
> >> > +               ((uint64_t)RREG32(RLC_GPU_CLOCK_COUNT_MSB) << 32);
> >>
> >> I keep forgeting about c type rules but i think you want 32ULL
> >
> > Not sure why that would be needed (or why you'd want it if it's not :).
> >
> 
> It's just about type conversion, i have been beat in the past by
> operation ending up as unsigned with << 32 and of course that means 0
> result which is not what you are looking for.

It's the type of the value on the left hand side of '<<' that matters
for that.


-- 
Earthling Michel Dänzer           |                   http://www.amd.com
Libre software enthusiast         |          Debian, X and DRI developer