Re: [Intel-gfx] [PATCH 3/3] drm/i915/dg2: add SNPS PHY translations for UHBR link rates

[Matt Roper <matthew.d.roper@intel.com>]

On Fri, Aug 13, 2021 at 02:51:51PM +0300, Jani Nikula wrote:
> UHBR link rates use different tx equalization settings. Using this will
> require changes in the link training code too.
> 
> Bspec: 53920
> Cc: Manasi Navare <manasi.d.navare@intel.com>
> Cc: Matt Roper <matthew.d.roper@intel.com>
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>

Matches the bspec values.

Reviewed-by: Matt Roper <matthew.d.roper@intel.com>

> ---
>  .../drm/i915/display/intel_ddi_buf_trans.c    | 29 ++++++++++++++++++-
>  1 file changed, 28 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi_buf_trans.c b/drivers/gpu/drm/i915/display/intel_ddi_buf_trans.c
> index ebb39624bfc9..796dd04eae01 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi_buf_trans.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi_buf_trans.c
> @@ -1002,6 +1002,30 @@ static const struct intel_ddi_buf_trans dg2_snps_translations = {
>  	.hdmi_default_entry = ARRAY_SIZE(_dg2_snps_translations) - 1,
>  };
>  
> +static const union intel_ddi_buf_trans_entry _dg2_snps_translations_uhbr[] = {
> +	{ .snps = { 62, 0, 0 } },	/* preset 0 */
> +	{ .snps = { 56, 0, 6 } },	/* preset 1 */
> +	{ .snps = { 51, 0, 11 } },	/* preset 2 */
> +	{ .snps = { 48, 0, 14 } },	/* preset 3 */
> +	{ .snps = { 43, 0, 19 } },	/* preset 4 */
> +	{ .snps = { 59, 3, 0 } },	/* preset 5 */
> +	{ .snps = { 53, 3, 6 } },	/* preset 6 */
> +	{ .snps = { 49, 3, 10 } },	/* preset 7 */
> +	{ .snps = { 45, 3, 14 } },	/* preset 8 */
> +	{ .snps = { 42, 3, 17 } },	/* preset 9 */
> +	{ .snps = { 56, 6, 0 } },	/* preset 10 */
> +	{ .snps = { 50, 6, 6 } },	/* preset 11 */
> +	{ .snps = { 47, 6, 9 } },	/* preset 12 */
> +	{ .snps = { 42, 6, 14 } },	/* preset 13 */
> +	{ .snps = { 46, 8, 8 } },	/* preset 14 */
> +	{ .snps = { 56, 3, 3 } },	/* preset 15 */
> +};
> +
> +static const struct intel_ddi_buf_trans dg2_snps_translations_uhbr = {
> +	.entries = _dg2_snps_translations_uhbr,
> +	.num_entries = ARRAY_SIZE(_dg2_snps_translations_uhbr),
> +};
> +
>  bool is_hobl_buf_trans(const struct intel_ddi_buf_trans *table)
>  {
>  	return table == &tgl_combo_phy_ddi_translations_edp_hbr2_hobl;
> @@ -1587,7 +1611,10 @@ dg2_get_snps_buf_trans(struct intel_encoder *encoder,
>  		       const struct intel_crtc_state *crtc_state,
>  		       int *n_entries)
>  {
> -	return intel_get_buf_trans(&dg2_snps_translations, n_entries);
> +	if (crtc_state->port_clock > 1000000)
> +		return intel_get_buf_trans(&dg2_snps_translations_uhbr, n_entries);
> +	else
> +		return intel_get_buf_trans(&dg2_snps_translations, n_entries);
>  }
>  
>  int intel_ddi_hdmi_num_entries(struct intel_encoder *encoder,
> -- 
> 2.20.1
> 

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