On Thu, Mar 16, 2023 at 03:17:14PM +0200, Imre Deak wrote:
> At least restoring the MST topology during system resume needs to use
> AUX before the display HW readout->sanitization sequence is complete,
> but on TC ports the PHY may be in the wrong mode for this, resulting in
> the AUX transfers to fail.
>
> The initial TC port mode is kept fixed as BIOS left it for the above HW
> readout sequence (to prevent changing the mode on an enabled port). If
> the port is disabled this initial mode is TBT - as in any case the PHY
> ownership is not held - even if a DP-alt sink is connected. Thus, the
> AUX transfers during this time will use TBT mode instead of the expected
> DP-alt mode and so time out.
>
> Fix the above by connecting the PHY during port initialization if the
> port is disabled, which will switch to the expected mode (DP-alt in the
> above case).
>
> As the encoder/pipe HW state isn't read-out yet at this point, check if
> the port is enabled based on the DDI_BUF enabled flag. Save the read-out
> initial mode, so intel_tc_port_sanitize_mode() can check this wrt. the
> read-out encoder HW state.
>
> Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
> ---
> .../drm/i915/display/intel_display_types.h | 1 +
> drivers/gpu/drm/i915/display/intel_tc.c | 48 +++++++++++++++++--
> 2 files changed, 46 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> index c32bfba06ca1f..06bbfd426ac70 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -1783,6 +1783,7 @@ struct intel_digital_port {
> bool tc_legacy_port:1;
> char tc_port_name[8];
> enum tc_port_mode tc_mode;
> + enum tc_port_mode tc_init_mode;
> enum phy_fia tc_phy_fia;
> u8 tc_phy_fia_idx;
>
> diff --git a/drivers/gpu/drm/i915/display/intel_tc.c b/drivers/gpu/drm/i915/display/intel_tc.c
> index fd826b9657e93..e8cf3b506fb7f 100644
> --- a/drivers/gpu/drm/i915/display/intel_tc.c
> +++ b/drivers/gpu/drm/i915/display/intel_tc.c
> @@ -118,6 +118,24 @@ assert_tc_cold_blocked(struct intel_digital_port *dig_port)
> drm_WARN_ON(&i915->drm, !enabled);
> }
>
> +static enum intel_display_power_domain
> +tc_port_power_domain(struct intel_digital_port *dig_port)
> +{
> + struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
> + enum tc_port tc_port = intel_port_to_tc(i915, dig_port->base.port);
> +
> + return POWER_DOMAIN_PORT_DDI_LANES_TC1 + tc_port - TC_PORT_1;
> +}
> +
> +static void
> +assert_tc_port_power_enabled(struct intel_digital_port *dig_port)
> +{
> + struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
> +
> + drm_WARN_ON(&i915->drm,
> + !intel_display_power_is_enabled(i915, tc_port_power_domain(dig_port)));
> +}
> +
> u32 intel_tc_port_get_lane_mask(struct intel_digital_port *dig_port)
> {
> struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
> @@ -670,6 +688,16 @@ static void __intel_tc_port_put_link(struct intel_digital_port *dig_port)
> dig_port->tc_link_refcount--;
> }
>
> +static bool tc_port_is_enabled(struct intel_digital_port *dig_port)
> +{
> + struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
> +
> + assert_tc_port_power_enabled(dig_port);
> +
> + return intel_de_read(i915, DDI_BUF_CTL(dig_port->base.port)) &
> + DDI_BUF_CTL_ENABLE;
> +}
> +
> /**
> * intel_tc_port_init_mode: Read out HW state and init the given port's TypeC mode
> * @dig_port: digital port
> @@ -692,9 +720,23 @@ void intel_tc_port_init_mode(struct intel_digital_port *dig_port)
> tc_cold_wref = tc_cold_block(dig_port, &domain);
>
> dig_port->tc_mode = intel_tc_port_get_current_mode(dig_port);
> + /*
> + * Save the initial mode for the state check in
> + * intel_tc_port_sanitize_mode().
> + */
> + dig_port->tc_init_mode = dig_port->tc_mode;
> + dig_port->tc_lock_wakeref = tc_cold_block(dig_port, &dig_port->tc_lock_power_domain);
> +
> + /*
> + * The PHY needs to be connected for AUX to work during HW readout and
> + * MST topology resume, but the PHY mode can only be changed if the
> + * port is disabled.
> + */
> + if (!tc_port_is_enabled(dig_port))
> + intel_tc_port_update_mode(dig_port, 1, false);
> +
> /* Prevent changing dig_port->tc_mode until intel_tc_port_sanitize_mode() is called. */
> __intel_tc_port_get_link(dig_port);
> - dig_port->tc_lock_wakeref = tc_cold_block(dig_port, &dig_port->tc_lock_power_domain);
>
> tc_cold_unblock(dig_port, domain, tc_cold_wref);
>
> @@ -741,11 +783,11 @@ void intel_tc_port_sanitize_mode(struct intel_digital_port *dig_port)
> * we'll just switch to disconnected mode from it here without
> * a note.
> */
> - if (dig_port->tc_mode != TC_PORT_TBT_ALT)
> + if (dig_port->tc_init_mode != TC_PORT_TBT_ALT)
> drm_dbg_kms(&i915->drm,
> "Port %s: PHY left in %s mode on disabled port, disconnecting it\n",
> dig_port->tc_port_name,
> - tc_port_mode_name(dig_port->tc_mode));
> + tc_port_mode_name(dig_port->tc_init_mode));
So we just have the tc_init_mode to get the debug correct,
or was it supposed be used elsewhere too?
> icl_tc_phy_disconnect(dig_port);
> __intel_tc_port_put_link(dig_port);
>
> --
> 2.37.1
--
Ville Syrjälä
Intel
