Quoting Jani Nikula (2025-10-15 12:33:31-03:00)
>On Wed, 15 Oct 2025, Gustavo Sousa <[email protected]> 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.
>>
>> Cc: Shekhar Chauhan <[email protected]>
>> Signed-off-by: Gustavo Sousa <[email protected]>
>> ---
>> drivers/gpu/drm/i915/display/intel_ddi.c | 7 +++++++
>> drivers/gpu/drm/i915/display/intel_display.c | 19 ++++++++++++++++++-
>> drivers/gpu/drm/i915/display/intel_display_types.h | 1 +
>> 3 files changed, 26 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c
>> b/drivers/gpu/drm/i915/display/intel_ddi.c
>> index c09aa759f4d4..6fcbebb81263 100644
>> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
>> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
>> @@ -5343,6 +5343,13 @@ void intel_ddi_init(struct intel_display *display,
>> goto err;
>> }
>>
>> + if (intel_bios_encoder_is_dedicated_external(devdata)) {
>> + dig_port->dedicated_external = true;
>> + drm_dbg_kms(display->drm,
>> + "Port %c is dedicated external\n",
>> + port_name(port));
>> + }
>
>With the information print added in parse_ddi_port(), the printing here
>becomes redundant.
>
>> +
>> 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 6ac718192e1c..46474199d1ab 100644
>> --- a/drivers/gpu/drm/i915/display/intel_display.c
>> +++ b/drivers/gpu/drm/i915/display/intel_display.c
>> @@ -1778,7 +1778,17 @@ 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)
>> {
>> /*
>> @@ -1863,6 +1873,13 @@ 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);
>> +
>> + if (dig_port->dedicated_external)
>
>Why go through all the trouble of duplicating the "decicated external"
>information in the digital port, when you already have encoder
>available, and can just use intel_bios_encoder_is_dedicated_external()
>right here?
I believe the last paragraph of the commit message explains the why.
Are you suggesting that we handle the lifespan issue right in this
series instead?
Using intel_bios_encoder_is_dedicated_external() my first approach, but
then we were hit with an oops because the VBT data was not available
anymore in the driver unbind path.
--
Gustavo Sousa
>
>> + 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 13652e2996a4..b5b9351501b1 100644
>> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
>> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
>> @@ -1909,6 +1909,7 @@ 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;
>
>--
>Jani Nikula, Intel
