Quoting Imre Deak (2025-11-12 13:24:30-03:00)
>On Fri, Nov 07, 2025 at 09:05:37PM -0300, Gustavo Sousa wrote:
>> Starting with Xe3p_LPD, the VBT has a new field, called in the driver
>> "dedicated_external", which tells that a Type-C capable port is
>> physically connected to a PHY outside of the Type-C subsystem. When
>> that's the case, the driver must not do the extra Type-C programming for
>> that port. Update intel_encoder_is_tc() to check for that case.
>>
>> While at it, add a note to intel_phy_is_tc() to remind us that it is
>> about whether the respective port is a Type-C capable port rather than
>> the PHY itself.
>>
>> (Maybe it would be a nice idea to rename intel_phy_is_tc()?)
>>
>> Note that this was handled with a new bool member added to struct
>> intel_digital_port instead of having querying the VBT directly because
>> VBT memory is freed (intel_bios_driver_remove) before encoder cleanup
>> (intel_ddi_encoder_destroy), which would cause an oops to happen when
>> the latter calls intel_encoder_is_tc(). This could be fixed by keeping
>> VBT data around longer, but that's left for a follow-up work, if deemed
>> necessary.
>>
>> v2:
>> - Drop printing info about dedicated external, now that we are doing
>> it when parsing the VBT. (Jani)
>> - Add a FIXME comment on the code explaining why we need to store
>> dedicated_external in struct intel_digital_port. (Jani)
>>
>> Cc: Jani Nikula <[email protected]>
>> Cc: Shekhar Chauhan <[email protected]>
>> Signed-off-by: Gustavo Sousa <[email protected]>
>> ---
>> drivers/gpu/drm/i915/display/intel_ddi.c | 11 +++++++++++
>> drivers/gpu/drm/i915/display/intel_display.c | 19 ++++++++++++++++++-
>> drivers/gpu/drm/i915/display/intel_display_types.h | 1 +
>> 3 files changed, 30 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c
>> b/drivers/gpu/drm/i915/display/intel_ddi.c
>> index 733ef4559131..d9aaeafd1570 100644
>> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
>> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
>> @@ -5376,6 +5376,17 @@ void intel_ddi_init(struct intel_display *display,
>> goto err;
>> }
>>
>> + /*
>> + * FIXME: We currently need to store dedicated_external because
>> devdata
>> + * does not live long enough for when intel_encoder_is_tc() is
>> called on
>> + * the unbind path. This needs to be fixed by making sure that the
>> VBT
>> + * data is kept long enough, so that
>> + * intel_bios_encoder_is_dedicated_external() can be called directly
>> + * from intel_encoder_is_tc().
>> + */
>> + if (intel_bios_encoder_is_dedicated_external(devdata))
>> + dig_port->dedicated_external = true;
>> +
>> if (intel_encoder_is_tc(encoder)) {
>> bool is_legacy =
>> !intel_bios_encoder_supports_typec_usb(devdata) &&
>> diff --git a/drivers/gpu/drm/i915/display/intel_display.c
>> b/drivers/gpu/drm/i915/display/intel_display.c
>> index 25986bd8fbdd..431f7f030a9b 100644
>> --- a/drivers/gpu/drm/i915/display/intel_display.c
>> +++ b/drivers/gpu/drm/i915/display/intel_display.c
>> @@ -1800,7 +1800,17 @@ bool intel_phy_is_combo(struct intel_display
>> *display, enum phy phy)
>> return false;
>> }
>>
>> -/* Prefer intel_encoder_is_tc() */
>> +/*
>> + * This function returns true if the DDI port respective to the PHY
>> enumeration
>> + * is a Type-C capable port.
>> + *
>> + * Depending on the VBT, the port might be configured
>> + * as a "dedicated external" port, meaning that actual physical PHY is
>> outside
>> + * of the Type-C subsystem and, as such, not really a "Type-C PHY".
>> + *
>> + * Prefer intel_encoder_is_tc(), especially if you really need to know if we
>> + * are dealing with Type-C connections.
>> + */
>> bool intel_phy_is_tc(struct intel_display *display, enum phy phy)
>> {
>> /*
>> @@ -1885,6 +1895,13 @@ bool intel_encoder_is_tc(struct intel_encoder
>> *encoder)
>> {
>> struct intel_display *display = to_intel_display(encoder);
>>
>> + if (intel_encoder_is_dig_port(encoder)) {
>> + struct intel_digital_port *dig_port =
>> enc_to_dig_port(encoder);
>
>Just dig_port = enc_to_dig_port(encoder); ... if (dig_port &&
>dig_port->dedicated_external) would be simpler and would be also more
>consistent wrt. MST encoders.
Ack.
Thanks!
--
Gustavo Sousa
>
>> +
>> + if (dig_port->dedicated_external)
>> + return false;
>> + }
>> +
>> return intel_phy_is_tc(display, intel_encoder_to_phy(encoder));
>> }
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
>> b/drivers/gpu/drm/i915/display/intel_display_types.h
>> index 00600134bda0..8bf392bc0d5d 100644
>> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
>> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
>> @@ -1937,6 +1937,7 @@ struct intel_digital_port {
>> bool lane_reversal;
>> bool ddi_a_4_lanes;
>> bool release_cl2_override;
>> + bool dedicated_external;
>> u8 max_lanes;
>> /* Used for DP and ICL+ TypeC/DP and TypeC/HDMI ports. */
>> enum aux_ch aux_ch;
>>
>> --
>> 2.51.0
>>
