On Thu, 04 Jun 2026, Michał Grzelak <[email protected]> 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 <[email protected]>
> Reviewed-by: Suraj Kandpal <[email protected]>
> ---
> 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
