[Intel-gfx] [PATCH] drm/i915/ehl: Update voltage level checks

[Matt Roper]

On Mon, Nov 18, 2019 at 08:44:12AM -0800, Matt Roper wrote:
> The bspec was recently updated with new cdclk -> voltage level tables to
> accomodate the new 324/326.4 cdclk values.
> 
> Bspec: 21809
> Cc: José Roberto de Souza <jose.souza at intel.com>
> Cc: Vivek Kasireddy <vivek.kasireddy at intel.com>
> Cc: Bob Paauwe <bob.j.paauwe at intel.com>
> Signed-off-by: Matt Roper <matthew.d.roper at intel.com>

And

Fixes: 63c9dae71dc5 ("drm/i915/ehl: Add voltage level requirement table")

since using the old table could result in us requesting too low a
voltage level for the highest cdclk values.


Matt

> ---
> There are some platform tagging issues on this bspec page and multiple
> tables are actually tagged with the EHL label, but the bspec changelog
> makes it pretty clear which table we're supposed to be using (plus the
> other tables don't match the set of cdclks supported by the platform).
> 
>  drivers/gpu/drm/i915/display/intel_cdclk.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c
> index 8b702317557e..7d1ab1e5b7c3 100644
> --- a/drivers/gpu/drm/i915/display/intel_cdclk.c
> +++ b/drivers/gpu/drm/i915/display/intel_cdclk.c
> @@ -1273,7 +1273,9 @@ static u8 icl_calc_voltage_level(int cdclk)
>  
>  static u8 ehl_calc_voltage_level(int cdclk)
>  {
> -	if (cdclk > 312000)
> +	if (cdclk > 326400)
> +		return 3;
> +	else if (cdclk > 312000)
>  		return 2;
>  	else if (cdclk > 180000)
>  		return 1;
> -- 
> 2.21.0
> 

-- 
Matt Roper
Graphics Software Engineer
VTT-OSGC Platform Enablement
Intel Corporation
(916) 356-2795