> -----Original Message-----
> From: Intel-gfx <intel-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of Imre
> Deak
> Sent: Thursday, March 16, 2023 3:17 PM
> To: intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> Subject: [PATCH 05/14] drm/i915/tc: Wait for IOM/FW PHY
> initialization of legacy TC ports
>
> During boot-up/system resume, the TC PHY on legacy ports will be initialized by
> the IOM/TCSS firmware regardless of a sink being connected or not (as opposed
> to DP-alt/TBT ports, which the FW only inits once a sink is connected).
>
> Wait for the above initialization to complete during HW readout, so that
> connecting the PHY later will already see the expected PHY ready state.
>
> Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_tc.c | 17 +++++++++++++++++
> 1 file changed, 17 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_tc.c
> b/drivers/gpu/drm/i915/display/intel_tc.c
> index e8cf3b506fb7f..2116c82831a53 100644
> --- a/drivers/gpu/drm/i915/display/intel_tc.c
> +++ b/drivers/gpu/drm/i915/display/intel_tc.c
> @@ -582,6 +582,15 @@ static bool icl_tc_phy_is_connected(struct
> intel_digital_port *dig_port)
> dig_port->tc_mode == TC_PORT_LEGACY; }
>
> +static void tc_phy_wait_for_ready(struct intel_digital_port *dig_port)
> +{
> + struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
> +
> + if (wait_for(tc_phy_status_complete(dig_port), 100))
> + drm_err(&i915->drm, "Port %s: timeout waiting for PHY
> ready\n",
This timeout value is probably based on experimentation as I couldn't find any specs for this.
Reviewed-by: Mika Kahola <mika.kahola@xxxxxxxxx>
> + dig_port->tc_port_name);
> +}
> +
> static enum tc_port_mode
> intel_tc_port_get_current_mode(struct intel_digital_port *dig_port) { @@ -
> 589,6 +598,14 @@ intel_tc_port_get_current_mode(struct intel_digital_port
> *dig_port)
> u32 live_status_mask = tc_port_live_status_mask(dig_port);
> enum tc_port_mode mode;
>
> + /*
> + * For legacy ports the IOM firmware initializes the PHY during boot-up
> + * and system resume whether or not a sink is connected. Wait here for
> + * the initialization to get ready.
> + */
> + if (dig_port->tc_legacy_port)
> + tc_phy_wait_for_ready(dig_port);
> +
> if (!tc_phy_is_owned(dig_port) ||
> drm_WARN_ON(&i915->drm, !tc_phy_status_complete(dig_port)))
> return TC_PORT_TBT_ALT;
> --
> 2.37.1
