Re: [PATCH 27/32] drm/i915/vbt: Add fields dedicated_external and dyn_port_over_tc

[Gustavo Sousa <gustavo.sousa@intel.com>]

Quoting Jani Nikula (2025-10-15 12:29:00-03:00)
>On Wed, 15 Oct 2025, Gustavo Sousa <gustavo.sousa@intel.com> wrote:
>> VBT version 264 adds new fields associated to Xe3p_LPD's new ways of
>> configuring SoC for TC ports and PHYs.  Update the code to match the
>> updates in VBT.
>>
>> The new field dedicated_external is used to represent TC ports that are
>> connected to PHYs outside of the Type-C subsystem, meaning that they
>> behave like dedicated ports and don't require the extra Type-C
>> programming.  In an upcoming change, we will update the driver to take
>> this field into consideration when detecting the type of port.
>>
>> The new field dyn_port_over_tc is used to inform that the TC port can be
>> dynamically allocated for a legacy connector in the Type-C subsystem,
>> which is a new feature in Xe3p_LPD.  In upcoming changes, we will use
>> that field in order to handle the IOM resource management programming
>> required for that.
>
>We probably want to add the info to print_ddi_port().

Yep.  Good idea.

I'm currently looking at print_ddi_port() and the one-liner is already
quite long and I don't know we would be able to come up with a good
abbreviation to put there.

Probably just print on its own line?
E.g.:

	dedicated_external = intel_bios_encoder_is_dedicated_external(devdata);
	if (dedicated_external)
		drm_dbg_kms(display->drm,
			    "Port %c is dedicated external\n");


Do you think printing for dyn_port_over_tc is also useful?

--
Gustavo Sousa

>
>>
>> Note that, when dedicated_external is set, the fields dp_usb_type_c and
>> tbt are tagged as "don't care" in the spec, so they should be ignored in
>> that case, so also make sure to update the accessor functions to take
>> that into consideration.
>>
>> Bspec: 20124, 68954, 74304
>> Cc: Shekhar Chauhan <shekhar.chauhan@intel.com>
>> Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com>
>> ---
>>  drivers/gpu/drm/i915/display/intel_bios.c     | 20 +++++++++++++++++++-
>>  drivers/gpu/drm/i915/display/intel_bios.h     |  2 ++
>>  drivers/gpu/drm/i915/display/intel_vbt_defs.h |  7 ++++++-
>>  3 files changed, 27 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
>> index 3596dce84c28..e466728ced0f 100644
>> --- a/drivers/gpu/drm/i915/display/intel_bios.c
>> +++ b/drivers/gpu/drm/i915/display/intel_bios.c
>> @@ -2777,7 +2777,7 @@ static int child_device_expected_size(u16 version)
>>  {
>>          BUILD_BUG_ON(sizeof(struct child_device_config) < 40);
>>  
>> -        if (version > 263)
>> +        if (version > 264)
>>                  return -ENOENT;
>>          else if (version >= 263)
>>                  return 44;
>> @@ -3714,14 +3714,32 @@ int intel_bios_hdmi_ddc_pin(const struct intel_bios_encoder_data *devdata)
>>  
>>  bool intel_bios_encoder_supports_typec_usb(const struct intel_bios_encoder_data *devdata)
>>  {
>> +        if (intel_bios_encoder_is_dedicated_external(devdata))
>> +                return false;
>> +
>>          return devdata->display->vbt.version >= 195 && devdata->child.dp_usb_type_c;
>>  }
>>  
>>  bool intel_bios_encoder_supports_tbt(const struct intel_bios_encoder_data *devdata)
>>  {
>> +        if (intel_bios_encoder_is_dedicated_external(devdata))
>> +                return false;
>> +
>>          return devdata->display->vbt.version >= 209 && devdata->child.tbt;
>>  }
>>  
>> +bool intel_bios_encoder_is_dedicated_external(const struct intel_bios_encoder_data *devdata)
>> +{
>> +        return devdata->display->vbt.version >= 264 &&
>> +                devdata->child.dedicated_external;
>> +}
>> +
>> +bool intel_bios_encoder_supports_dyn_port_over_tc(const struct intel_bios_encoder_data *devdata)
>> +{
>> +        return devdata->display->vbt.version >= 264 &&
>> +                devdata->child.dyn_port_over_tc;
>> +}
>> +
>>  bool intel_bios_encoder_lane_reversal(const struct intel_bios_encoder_data *devdata)
>>  {
>>          return devdata && devdata->child.lane_reversal;
>> diff --git a/drivers/gpu/drm/i915/display/intel_bios.h b/drivers/gpu/drm/i915/display/intel_bios.h
>> index f9e438b2787b..75dff27b4228 100644
>> --- a/drivers/gpu/drm/i915/display/intel_bios.h
>> +++ b/drivers/gpu/drm/i915/display/intel_bios.h
>> @@ -79,6 +79,8 @@ bool intel_bios_encoder_supports_dp(const struct intel_bios_encoder_data *devdat
>>  bool intel_bios_encoder_supports_edp(const struct intel_bios_encoder_data *devdata);
>>  bool intel_bios_encoder_supports_typec_usb(const struct intel_bios_encoder_data *devdata);
>>  bool intel_bios_encoder_supports_tbt(const struct intel_bios_encoder_data *devdata);
>> +bool intel_bios_encoder_is_dedicated_external(const struct intel_bios_encoder_data *devdata);
>> +bool intel_bios_encoder_supports_dyn_port_over_tc(const struct intel_bios_encoder_data *devdata);
>>  bool intel_bios_encoder_supports_dsi(const struct intel_bios_encoder_data *devdata);
>>  bool intel_bios_encoder_supports_dp_dual_mode(const struct intel_bios_encoder_data *devdata);
>>  bool intel_bios_encoder_is_lspcon(const struct intel_bios_encoder_data *devdata);
>> diff --git a/drivers/gpu/drm/i915/display/intel_vbt_defs.h b/drivers/gpu/drm/i915/display/intel_vbt_defs.h
>> index 70e31520c560..f07ab64a8d97 100644
>> --- a/drivers/gpu/drm/i915/display/intel_vbt_defs.h
>> +++ b/drivers/gpu/drm/i915/display/intel_vbt_defs.h
>> @@ -554,7 +554,12 @@ struct child_device_config {
>>          u8 dvo_function;
>>          u8 dp_usb_type_c:1;                                        /* 195+ */
>>          u8 tbt:1;                                                /* 209+ */
>> -        u8 flags2_reserved:2;                                        /* 195+ */
>> +        /*
>> +         * Fields dp_usb_type_c and tbt must be ignored when
>> +         * dedicated_external is set.
>> +         */
>> +        u8 dedicated_external:1;                                /* 264+ */
>> +        u8 dyn_port_over_tc:1;                                        /* 264+ */
>>          u8 dp_port_trace_length:4;                                /* 209+ */
>>          u8 dp_gpio_index;                                        /* 195+ */
>>          u16 dp_gpio_pin_num;                                        /* 195+ */
>
>-- 
>Jani Nikula, Intel