Re: [PATCH 38/49] drm/i915: check for div-by-zero in vlv_PLL_is_optimal

Daniel Vetter
2015-03-20T09:58:38Z

On Thu, Mar 19, 2015 at 01:31:44PM -0700, Jesse Barnes wrote:
> On 03/17/2015 02:40 AM, Imre Deak wrote:
> > Signed-off-by: Imre Deak <imre.deak@intel.com>
> > ---
> > drivers/gpu/drm/i915/intel_display.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> > index 7feb047..5874512 100644
> > --- a/drivers/gpu/drm/i915/intel_display.c
> > +++ b/drivers/gpu/drm/i915/intel_display.c
> > @@ -786,6 +786,9 @@ static bool vlv_PLL_is_optimal(struct drm_device *dev, int target_freq,
> > unsigned int best_error_ppm,
> > unsigned int *error_ppm)
> > {
> > + if (WARN_ON_ONCE(!target_freq))
> > + return false;
> > +
> > *error_ppm = div_u64(1000000ULL *
> > abs(target_freq - calculated_clock->dot),
> > target_freq);
> >
>
> Thank you. This one bites a lot in debug.
>
> Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>

I went ahead and merged these 2 prep patches to dinq right away.

Thanks, Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation