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

Jesse Barnes
2015-03-19T20:32:26Z

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>