On Tue, 2021-09-21 at 03:23 +0300, Imre Deak wrote:
> So far TC-cold was blocked only for the duration of TypeC mode resets.
> The DP-alt and legacy modes require TC-cold to be blocked also whenever
> the port is in use (AUX transfers, enable modeset), and this was ensured
> by the held PHY ownership flag. On ADL-P this doesn't work, since the
> PHY ownership flag is in a register backed by the PW#2 power well.
> Whenever this power well is disabled the ownership flag is cleared by
> the HW under the driver.
>
> The only way to cleanly release and re-acquire the PHY ownership flag
> and also allow for power saving (by disabling the display power wells
> and reaching DC5/6 states) is to hold the TC-cold blocking power domains
> while the PHY is connected and disconnect/reconnect the PHY on-demand
> around AUX transfers and modeset enable/disables. Let's do that,
> disconnecting a PHY with a 1 sec delay after it becomes idle. For
> consistency do this on all platforms and TypeC modes.
Reviewed-by: José Roberto de Souza <jose.souza@xxxxxxxxx>
>
> Cc: José Roberto de Souza <jose.souza@xxxxxxxxx>
> Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_ddi.c | 7 +-
> .../drm/i915/display/intel_display_types.h | 1 +
> drivers/gpu/drm/i915/display/intel_tc.c | 87 +++++++++++--------
> drivers/gpu/drm/i915/display/intel_tc.h | 2 +-
> 4 files changed, 60 insertions(+), 37 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> index b9194d6a4dfe7..b509d5f2d5f0e 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -4019,8 +4019,11 @@ static void intel_ddi_encoder_destroy(struct drm_encoder *encoder)
> {
> struct drm_i915_private *i915 = to_i915(encoder->dev);
> struct intel_digital_port *dig_port = enc_to_dig_port(to_intel_encoder(encoder));
> + enum phy phy = intel_port_to_phy(i915, dig_port->base.port);
>
> intel_dp_encoder_flush_work(encoder);
> + if (intel_phy_is_tc(i915, phy))
> + intel_tc_port_flush_work(dig_port);
> intel_display_power_flush_work(i915);
>
> drm_encoder_cleanup(encoder);
> @@ -4445,7 +4448,7 @@ static void intel_ddi_encoder_suspend(struct intel_encoder *encoder)
> if (!intel_phy_is_tc(i915, phy))
> return;
>
> - intel_tc_port_disconnect_phy(dig_port);
> + intel_tc_port_flush_work(dig_port);
> }
>
> static void intel_ddi_encoder_shutdown(struct intel_encoder *encoder)
> @@ -4460,7 +4463,7 @@ static void intel_ddi_encoder_shutdown(struct intel_encoder *encoder)
> if (!intel_phy_is_tc(i915, phy))
> return;
>
> - intel_tc_port_disconnect_phy(dig_port);
> + intel_tc_port_flush_work(dig_port);
> }
>
> #define port_tc_name(port) ((port) - PORT_TC1 + '1')
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> index 08a73ffded957..53509f6ae3d10 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -1667,6 +1667,7 @@ struct intel_digital_port {
> struct mutex tc_lock; /* protects the TypeC port mode */
> intel_wakeref_t tc_lock_wakeref;
> enum intel_display_power_domain tc_lock_power_domain;
> + struct delayed_work tc_disconnect_phy_work;
> int tc_link_refcount;
> bool tc_legacy_port:1;
> char tc_port_name[8];
> diff --git a/drivers/gpu/drm/i915/display/intel_tc.c b/drivers/gpu/drm/i915/display/intel_tc.c
> index 8d799cf7ccefd..3fefd00e04685 100644
> --- a/drivers/gpu/drm/i915/display/intel_tc.c
> +++ b/drivers/gpu/drm/i915/display/intel_tc.c
> @@ -645,6 +645,13 @@ static void intel_tc_port_update_mode(struct intel_digital_port *dig_port,
>
> intel_tc_port_reset_mode(dig_port, required_lanes, force_disconnect);
>
> + /* Get power domain matching the new mode after reset. */
> + tc_cold_unblock(dig_port, dig_port->tc_lock_power_domain,
> + fetch_and_zero(&dig_port->tc_lock_wakeref));
> + if (dig_port->tc_mode != TC_PORT_DISCONNECTED)
> + dig_port->tc_lock_wakeref = tc_cold_block(dig_port,
> + &dig_port->tc_lock_power_domain);
> +
> tc_cold_unblock(dig_port, domain, wref);
> }
>
> @@ -672,6 +679,7 @@ void intel_tc_port_sanitize(struct intel_digital_port *dig_port)
> active_links = to_intel_crtc(encoder->base.crtc)->active;
>
> drm_WARN_ON(&i915->drm, dig_port->tc_mode != TC_PORT_DISCONNECTED);
> + drm_WARN_ON(&i915->drm, dig_port->tc_lock_wakeref);
> if (active_links) {
> enum intel_display_power_domain domain;
> intel_wakeref_t tc_cold_wref = tc_cold_block(dig_port, &domain);
> @@ -684,6 +692,9 @@ void intel_tc_port_sanitize(struct intel_digital_port *dig_port)
> dig_port->tc_port_name, active_links);
> intel_tc_port_link_init_refcount(dig_port, active_links);
>
> + 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);
> }
>
> @@ -724,60 +735,67 @@ bool intel_tc_port_connected(struct intel_encoder *encoder)
> }
>
> static void __intel_tc_port_lock(struct intel_digital_port *dig_port,
> - int required_lanes, bool force_disconnect)
> + int required_lanes)
> {
> struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
> - intel_wakeref_t wakeref;
> -
> - wakeref = intel_display_power_get(i915, POWER_DOMAIN_DISPLAY_CORE);
>
> mutex_lock(&dig_port->tc_lock);
>
> + cancel_delayed_work(&dig_port->tc_disconnect_phy_work);
>
> if (!dig_port->tc_link_refcount)
> intel_tc_port_update_mode(dig_port, required_lanes,
> - force_disconnect);
> + false);
>
> drm_WARN_ON(&i915->drm, dig_port->tc_mode == TC_PORT_DISCONNECTED);
> drm_WARN_ON(&i915->drm, dig_port->tc_mode != TC_PORT_TBT_ALT &&
> !tc_phy_is_owned(dig_port));
> -
> - drm_WARN_ON(&i915->drm, dig_port->tc_lock_wakeref);
> - dig_port->tc_lock_wakeref = wakeref;
> }
>
> void intel_tc_port_lock(struct intel_digital_port *dig_port)
> {
> - __intel_tc_port_lock(dig_port, 1, false);
> -}
> -
> -void intel_tc_port_unlock(struct intel_digital_port *dig_port)
> -{
> - struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
> - intel_wakeref_t wakeref = fetch_and_zero(&dig_port->tc_lock_wakeref);
> -
> - mutex_unlock(&dig_port->tc_lock);
> -
> - intel_display_power_put_async(i915, POWER_DOMAIN_DISPLAY_CORE,
> - wakeref);
> + __intel_tc_port_lock(dig_port, 1);
> }
>
> /**
> - * intel_tc_port_disconnect_phy: disconnect TypeC PHY from display port
> + * intel_tc_port_disconnect_phy_work: disconnect TypeC PHY from display port
> * @dig_port: digital port
> *
> * Disconnect the given digital port from its TypeC PHY (handing back the
> - * control of the PHY to the TypeC subsystem). The only purpose of this
> - * function is to force the disconnect even with a TypeC display output still
> - * plugged to the TypeC connector, which is required by the TypeC firmwares
> - * during system suspend and shutdown. Otherwise - during the unplug event
> - * handling - the PHY ownership is released automatically by
> - * intel_tc_port_reset_mode(), when calling this function is not required.
> + * control of the PHY to the TypeC subsystem). This will happen in a delayed
> + * manner after each aux transactions and modeset disables.
> */
> -void intel_tc_port_disconnect_phy(struct intel_digital_port *dig_port)
> +static void intel_tc_port_disconnect_phy_work(struct work_struct *work)
> {
> - __intel_tc_port_lock(dig_port, 1, true);
> - intel_tc_port_unlock(dig_port);
> + struct intel_digital_port *dig_port =
> + container_of(work, struct intel_digital_port, tc_disconnect_phy_work.work);
> +
> + mutex_lock(&dig_port->tc_lock);
> +
> + if (!dig_port->tc_link_refcount)
> + intel_tc_port_update_mode(dig_port, 1, true);
> +
> + mutex_unlock(&dig_port->tc_lock);
> +}
> +
> +/**
> + * intel_tc_port_flush_work: flush the work disconnecting the PHY
> + * @dig_port: digital port
> + *
> + * Flush the delayed work disconnecting an idle PHY.
> + */
> +void intel_tc_port_flush_work(struct intel_digital_port *dig_port)
> +{
> + flush_delayed_work(&dig_port->tc_disconnect_phy_work);
> +}
> +
> +void intel_tc_port_unlock(struct intel_digital_port *dig_port)
> +{
> + if (!dig_port->tc_link_refcount && dig_port->tc_mode != TC_PORT_DISCONNECTED)
> + queue_delayed_work(system_unbound_wq, &dig_port->tc_disconnect_phy_work,
> + msecs_to_jiffies(1000));
> +
> + mutex_unlock(&dig_port->tc_lock);
> }
>
> bool intel_tc_port_ref_held(struct intel_digital_port *dig_port)
> @@ -789,16 +807,16 @@ bool intel_tc_port_ref_held(struct intel_digital_port *dig_port)
> void intel_tc_port_get_link(struct intel_digital_port *dig_port,
> int required_lanes)
> {
> - __intel_tc_port_lock(dig_port, required_lanes, false);
> + __intel_tc_port_lock(dig_port, required_lanes);
> dig_port->tc_link_refcount++;
> intel_tc_port_unlock(dig_port);
> }
>
> void intel_tc_port_put_link(struct intel_digital_port *dig_port)
> {
> - mutex_lock(&dig_port->tc_lock);
> - dig_port->tc_link_refcount--;
> - mutex_unlock(&dig_port->tc_lock);
> + intel_tc_port_lock(dig_port);
> + --dig_port->tc_link_refcount;
> + intel_tc_port_unlock(dig_port);
> }
>
> static bool
> @@ -854,6 +872,7 @@ void intel_tc_port_init(struct intel_digital_port *dig_port, bool is_legacy)
> "%c/TC#%d", port_name(port), tc_port + 1);
>
> mutex_init(&dig_port->tc_lock);
> + INIT_DELAYED_WORK(&dig_port->tc_disconnect_phy_work, intel_tc_port_disconnect_phy_work);
> dig_port->tc_legacy_port = is_legacy;
> dig_port->tc_mode = TC_PORT_DISCONNECTED;
> dig_port->tc_link_refcount = 0;
> diff --git a/drivers/gpu/drm/i915/display/intel_tc.h b/drivers/gpu/drm/i915/display/intel_tc.h
> index 0fdcddb4fc870..6b47b29f551c9 100644
> --- a/drivers/gpu/drm/i915/display/intel_tc.h
> +++ b/drivers/gpu/drm/i915/display/intel_tc.h
> @@ -17,7 +17,6 @@ bool intel_tc_port_in_dp_alt_mode(struct intel_digital_port *dig_port);
> bool intel_tc_port_in_legacy_mode(struct intel_digital_port *dig_port);
>
> bool intel_tc_port_connected(struct intel_encoder *encoder);
> -void intel_tc_port_disconnect_phy(struct intel_digital_port *dig_port);
>
> u32 intel_tc_port_get_lane_mask(struct intel_digital_port *dig_port);
> u32 intel_tc_port_get_pin_assignment_mask(struct intel_digital_port *dig_port);
> @@ -28,6 +27,7 @@ void intel_tc_port_set_fia_lane_count(struct intel_digital_port *dig_port,
> void intel_tc_port_sanitize(struct intel_digital_port *dig_port);
> void intel_tc_port_lock(struct intel_digital_port *dig_port);
> void intel_tc_port_unlock(struct intel_digital_port *dig_port);
> +void intel_tc_port_flush_work(struct intel_digital_port *dig_port);
> void intel_tc_port_get_link(struct intel_digital_port *dig_port,
> int required_lanes);
> void intel_tc_port_put_link(struct intel_digital_port *dig_port);
