On Thu, Aug 12, 2021 at 11:18:03AM +0530, Animesh Manna wrote:
> From: Jani Nikula <jani.nikula@xxxxxxxxx>
>
> Combo phy is limited to 5.4 GHz on low-voltage SKUs. Combo phy DP is
> limited to 5.4 GHz, while combo phy eDP can do 8.1 GHz.
>
> Bspec: 20584, 20598, 49180, 49201
>
> Cc: Imre Deak <imre.deak@xxxxxxxxx>
> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
> Signed-off-by: Animesh Manna <animesh.manna@xxxxxxxxx>
Reviewed-by: Imre Deak <imre.deak@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_dp.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 4df56af36b3f..42b29948bc72 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -224,6 +224,15 @@ bool intel_dp_can_bigjoiner(struct intel_dp *intel_dp)
> encoder->port != PORT_A);
> }
>
> +static bool is_low_voltage_sku(struct drm_i915_private *i915, enum phy phy)
> +{
> + u32 voltage;
> +
> + voltage = intel_de_read(i915, ICL_PORT_COMP_DW3(phy)) & VOLTAGE_INFO_MASK;
> +
> + return voltage == VOLTAGE_INFO_0_85V;
> +}
> +
> static int icl_max_source_rate(struct intel_dp *intel_dp)
> {
> struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
> @@ -231,7 +240,7 @@ static int icl_max_source_rate(struct intel_dp *intel_dp)
> enum phy phy = intel_port_to_phy(dev_priv, dig_port->base.port);
>
> if (intel_phy_is_combo(dev_priv, phy) &&
> - !intel_dp_is_edp(intel_dp))
> + (is_low_voltage_sku(dev_priv, phy) || !intel_dp_is_edp(intel_dp)))
> return 540000;
>
> return 810000;
> --
> 2.29.0
>
