Re: [Intel-gfx] [PATCH 1/2] drm/i915/dp: Define each HBR link rate

[Jani Nikula <jani.nikula@linux.intel.com>]

On Mon, 02 Dec 2019, José Roberto de Souza <jose.souza@intel.com> wrote:
> This is better than keep those values in the code that you always
> need to check the DP spec to know what level of HBR it is.
>
> Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_ddi.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> index a976606d21c7..914f0cc4d237 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -49,6 +49,10 @@
>  #include "intel_tc.h"
>  #include "intel_vdsc.h"
>  
> +#define HBR_RATE 270000
> +#define HBR2_RATE 540000
> +#define HBR3_RATE 810000
> +
>  struct ddi_buf_trans {
>  	u32 trans1;	/* balance leg enable, de-emph level */
>  	u32 trans2;	/* vref sel, vswing */
> @@ -888,7 +892,7 @@ icl_get_combo_buf_trans(struct drm_i915_private *dev_priv, int type, int rate,
>  	if (type == INTEL_OUTPUT_HDMI) {
>  		*n_entries = ARRAY_SIZE(icl_combo_phy_ddi_translations_hdmi);
>  		return icl_combo_phy_ddi_translations_hdmi;
> -	} else if (rate > 540000 && type == INTEL_OUTPUT_EDP) {
> +	} else if (rate > HBR2_RATE && type == INTEL_OUTPUT_EDP) {

I don't want a patch switching some random place to using a
macro. Either we stick to numbers or switch all.

And if switch all, add the rates to drm core, not locally to
intel_ddi.c. (And then wonder what to do with the intermediate rates in
intel_dp_set_source_rates()...)

Personally, HBR<N> is less useful to me in code, it's the actual rate
that helps me.

But I'll trust Ville's judgement on this one.

BR,
Jani.


>  		*n_entries = ARRAY_SIZE(icl_combo_phy_ddi_translations_edp_hbr3);
>  		return icl_combo_phy_ddi_translations_edp_hbr3;
>  	} else if (type == INTEL_OUTPUT_EDP && dev_priv->vbt.edp.low_vswing) {

-- 
Jani Nikula, Intel Open Source Graphics Center
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