[Intel-gfx] [PATCH 1/2] drm/i915: Use mul_u32_u32() more

[Chris Wilson]

Quoting Ville Syrjala (2019-04-08 16:27:01)
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> We have a lot of '(u64)foo * bar' everywhere. Replace with
> mul_u32_u32() to avoid gcc failing to use a regular 32x32->64
> multiply for this.
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

As a purely mechanical translation,
Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>

> diff --git a/drivers/gpu/drm/i915/intel_dpll_mgr.c b/drivers/gpu/drm/i915/intel_dpll_mgr.c
> index e01c057ce50b..29edc369920b 100644
> --- a/drivers/gpu/drm/i915/intel_dpll_mgr.c
> +++ b/drivers/gpu/drm/i915/intel_dpll_mgr.c
> @@ -2741,11 +2741,11 @@ static bool icl_calc_mg_pll_state(struct intel_crtc_state *crtc_state)
>         }
>  
>         if (use_ssc) {
> -               tmp = (u64)dco_khz * 47 * 32;
> +               tmp = mul_u32_u32(dco_khz, 47 * 32);
>                 do_div(tmp, refclk_khz * m1div * 10000);
>                 ssc_stepsize = tmp;
>  
> -               tmp = (u64)dco_khz * 1000;
> +               tmp = mul_u32_u32(dco_khz, 1000);

These caught my eye, wondering if the code was better reduced if the
constant was first or itself cast to (u64).
-Chris