Re: [PATCH v6 3/8] drm/i915/bios: print VS/PE-O port info

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

On Thu, 04 Jun 2026, Michał Grzelak <michal.grzelak@intel.com> wrote:
> Issue a debug message when port asks to override default Vswing /
> Preemphasis tables.
>
> Add helper intel_bios_encoder_requests_vspeo() to check if port
> requests for overriding default VS/PE tables.
>
> v3->v4
> - change debug message when requesting VS/PE-O (Suraj)
>
> Signed-off-by: Michał Grzelak <michal.grzelak@intel.com>
> Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_bios.c | 10 ++++++++++
>  drivers/gpu/drm/i915/display/intel_bios.h |  1 +
>  2 files changed, 11 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
> index d071f0e5d4380..204176088a7cd 100644
> --- a/drivers/gpu/drm/i915/display/intel_bios.c
> +++ b/drivers/gpu/drm/i915/display/intel_bios.c
> @@ -2781,6 +2781,11 @@ static void print_ddi_port(const struct intel_bios_encoder_data *devdata)
>  			    "Port %c supports dynamic DDI allocation in TCSS\n",
>  			    port_name(port));
>  
> +	if (intel_bios_encoder_requests_vspeo(devdata))
> +		drm_dbg_kms(display->drm,
> +			    "Port %c requests VS/PE-O\n",

I don't think it's helpful to use these acronyms in debug logging.

"vswing/pre-emphasis override"

> +			    port_name(port));
> +
>  	hdmi_level_shift = intel_bios_hdmi_level_shift(devdata);
>  	if (hdmi_level_shift >= 0) {
>  		drm_dbg_kms(display->drm,
> @@ -3809,6 +3814,11 @@ int intel_bios_hdmi_ddc_pin(const struct intel_bios_encoder_data *devdata)
>  	return map_ddc_pin(devdata->display, devdata->child.ddc_pin);
>  }
>  
> +bool intel_bios_encoder_requests_vspeo(const struct intel_bios_encoder_data *devdata)
> +{
> +	return devdata->display->vbt.version >= 218 && devdata->child.use_vbt_vswing;
> +}
> +
>  bool intel_bios_encoder_supports_typec_usb(const struct intel_bios_encoder_data *devdata)
>  {
>  	return devdata->display->vbt.version >= 195 && devdata->child.dp_usb_type_c;
> diff --git a/drivers/gpu/drm/i915/display/intel_bios.h b/drivers/gpu/drm/i915/display/intel_bios.h
> index 75dff27b42289..7a50a272cd27d 100644
> --- a/drivers/gpu/drm/i915/display/intel_bios.h
> +++ b/drivers/gpu/drm/i915/display/intel_bios.h
> @@ -73,6 +73,7 @@ bool intel_bios_get_dsc_params(struct intel_encoder *encoder,
>  const struct intel_bios_encoder_data *
>  intel_bios_encoder_data_lookup(struct intel_display *display, enum port port);
>  
> +bool intel_bios_encoder_requests_vspeo(const struct intel_bios_encoder_data *devdata);
>  bool intel_bios_encoder_supports_dvi(const struct intel_bios_encoder_data *devdata);
>  bool intel_bios_encoder_supports_hdmi(const struct intel_bios_encoder_data *devdata);
>  bool intel_bios_encoder_supports_dp(const struct intel_bios_encoder_data *devdata);

-- 
Jani Nikula, Intel