Commit 3e0abc76 authored by Imre Deak's avatar Imre Deak
Browse files

drm/i915/tc: Fix TypeC PHY connect/disconnect logic on ADL-P 



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.

v2: Add tc_mode!=disconnected and phy_is_owned asserts to
    __intel_tc_port_lock().

Cc: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: default avatarImre Deak <imre.deak@intel.com>
Reviewed-by: default avatarJosé Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210929132833.2253961-6-imre.deak@intel.com
parent 38c39346

drivers/gpu/drm/i915/display/intel_ddi.c

+5 −2
Original line number Diff line number Diff line
@@ -4017,8 +4017,11 @@ 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);
@@ -4443,7 +4446,7 @@ 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)
@@ -4458,7 +4461,7 @@ 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')

drivers/gpu/drm/i915/display/intel_display_types.h

+1 −0
Original line number Diff line number Diff line
@@ -1666,6 +1666,7 @@ 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];

drivers/gpu/drm/i915/display/intel_tc.c

+52 −29
Original line number Diff line number Diff line
@@ -666,6 +666,13 @@ 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);

}
@@ -693,6 +700,7 @@ 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);
@@ -705,6 +713,9 @@ 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);

	}
@@ -745,56 +756,67 @@ 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_lock_wakeref);

	dig_port->tc_lock_wakeref = wakeref;

	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));

}



void intel_tc_port_lock(struct intel_digital_port *dig_port)

{

	__intel_tc_port_lock(dig_port, 1, false);

	__intel_tc_port_lock(dig_port, 1);

}



void intel_tc_port_unlock(struct intel_digital_port *dig_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). This will happen in a delayed

 * manner after each aux transactions and modeset disables.

 */

static void intel_tc_port_disconnect_phy_work(struct work_struct *work)

{

	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);

	intel_wakeref_t wakeref = fetch_and_zero(&dig_port->tc_lock_wakeref);

	struct intel_digital_port *dig_port =

		container_of(work, struct intel_digital_port, tc_disconnect_phy_work.work);



	mutex_unlock(&dig_port->tc_lock);

	mutex_lock(&dig_port->tc_lock);



	if (!dig_port->tc_link_refcount)

		intel_tc_port_update_mode(dig_port, 1, true);



	intel_display_power_put_async(i915, POWER_DOMAIN_DISPLAY_CORE,

				      wakeref);

	mutex_unlock(&dig_port->tc_lock);

}



/**

 * intel_tc_port_disconnect_phy: disconnect TypeC PHY from display port

 * intel_tc_port_flush_work: flush the work disconnecting the PHY

 * @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.

 * Flush the delayed work disconnecting an idle PHY.

 */

void intel_tc_port_disconnect_phy(struct intel_digital_port *dig_port)

void intel_tc_port_flush_work(struct intel_digital_port *dig_port)

{

	__intel_tc_port_lock(dig_port, 1, true);

	intel_tc_port_unlock(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)
@@ -806,16 +828,16 @@ 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
@@ -871,6 +893,7 @@ 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;

drivers/gpu/drm/i915/display/intel_tc.h

+1 −1
Original line number Diff line number Diff line
@@ -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);