linux/drivers/gpu/drm/i915/display/intel_hotplug.h

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/* SPDX-License-Identifier: MIT */
/*
* Copyright © 2019 Intel Corporation
*/
#ifndef __INTEL_HOTPLUG_H__
#define __INTEL_HOTPLUG_H__
#include <linux/types.h>
enum port;
struct intel_connector;
drm/i915/dp_mst: Work around out-of-spec adapters filtering short pulses Some TypeC -> native DP adapters, at least the Club 3D CAC-1557 adapter, incorrectly filter out HPD short pulses with a duration less than ~540 usec, leading to MST probe failures. According to the DP Standard 2.0 section 5.1.4: - DP sinks should generate short pulses in the 500 usec -> 1 msec range - DP sources should detect short pulses in the 250 usec -> 2 msec range According to the DP Alt Mode on TypeC Standard section 3.9.2, adapters should detect and forward short pulses according to how sources should detect them as specified in the DP Standard (250 usec -> 2 msec). Based on the above filtering out short pulses with a duration less than 540 usec is incorrect. To make such adapters work add support for a driver polling on MST inerrupt flags, and wire this up in the i915 driver. The sink can clear an interrupt it raised after 110 msec if the source doesn't respond, so use a 50 msec poll period to avoid missing an interrupt. Polling of the MST interrupt flags is explicitly allowed by the DP Standard. This fixes MST probe failures I saw using this adapter and a DELL U2515H monitor. v2: - Fix the wait event timeout for the no-poll case. v3 (Ville): - Fix the short pulse duration limits in the commit log prescribed by the DP Standard. - Add code comment explaining why/how polling is used. - Factor out a helper to schedule the port's hpd irq handler and move it to the rest of hotplug handlers. - Document the new MST callback. - s/update_hpd_irq_state/poll_hpd_irq/ Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200604184500.23730-2-imre.deak@intel.com
2020-06-04 21:45:00 +03:00
struct intel_digital_port;
struct intel_display;
struct intel_encoder;
void intel_hpd_poll_enable(struct intel_display *display);
void intel_hpd_poll_disable(struct intel_display *display);
void intel_hpd_poll_fini(struct intel_display *display);
enum intel_hotplug_state intel_encoder_hotplug(struct intel_encoder *encoder,
struct intel_connector *connector);
void intel_hpd_irq_handler(struct intel_display *display,
u32 pin_mask, u32 long_mask);
drm/i915/dp_mst: Work around out-of-spec adapters filtering short pulses Some TypeC -> native DP adapters, at least the Club 3D CAC-1557 adapter, incorrectly filter out HPD short pulses with a duration less than ~540 usec, leading to MST probe failures. According to the DP Standard 2.0 section 5.1.4: - DP sinks should generate short pulses in the 500 usec -> 1 msec range - DP sources should detect short pulses in the 250 usec -> 2 msec range According to the DP Alt Mode on TypeC Standard section 3.9.2, adapters should detect and forward short pulses according to how sources should detect them as specified in the DP Standard (250 usec -> 2 msec). Based on the above filtering out short pulses with a duration less than 540 usec is incorrect. To make such adapters work add support for a driver polling on MST inerrupt flags, and wire this up in the i915 driver. The sink can clear an interrupt it raised after 110 msec if the source doesn't respond, so use a 50 msec poll period to avoid missing an interrupt. Polling of the MST interrupt flags is explicitly allowed by the DP Standard. This fixes MST probe failures I saw using this adapter and a DELL U2515H monitor. v2: - Fix the wait event timeout for the no-poll case. v3 (Ville): - Fix the short pulse duration limits in the commit log prescribed by the DP Standard. - Add code comment explaining why/how polling is used. - Factor out a helper to schedule the port's hpd irq handler and move it to the rest of hotplug handlers. - Document the new MST callback. - s/update_hpd_irq_state/poll_hpd_irq/ Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Lyude Paul <lyude@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20200604184500.23730-2-imre.deak@intel.com
2020-06-04 21:45:00 +03:00
void intel_hpd_trigger_irq(struct intel_digital_port *dig_port);
void intel_hpd_init(struct intel_display *display);
void intel_hpd_init_early(struct intel_display *display);
void intel_hpd_cancel_work(struct intel_display *display);
enum hpd_pin intel_hpd_pin_default(enum port port);
drm/i915/hpd: Add support for blocking the IRQ handling on an HPD pin Add support for blocking the IRQ handling on the HPD pin of a given encoder, handling IRQs that arrived while in the blocked state after unblocking the IRQ handling. This will be used by a follow-up change, which blocks/unblocks the IRQ handling around DP link training. This is similar to the intel_hpd_disable/enable() functionality, by also handling encoders/ports with a pulse handler (i.e. also blocking/unblocking the short/long pulse handling) and handling the IRQs arrived in the blocked state after the handling is unblocked (vs. just dropping such IRQs). v2: - Handle encoders without a port assigned to them. - Fix clearing IRQs from intel_hotplug::short_port_mask. v3: - Rename intel_hpd_suspend/resume() to intel_hpd_block/unblock(). (Jani) - Refer to HPD pins as hpd_pin vs. hpd. - Flush dig_port_work in intel_hpd_block() if any encoder using the HPD pin has a pulse handler. v4: - Fix hpd_pin_has_pulse(), checking the encoder's HPD pin. v5: - Rebase on port->hpd_pin tracking. (Ville) v6: (Jani) - Add hpd_pin_is_blocked() helper. - Use the hpd_pin_mask term for a mask of pins instead of hpd_pins. - Prevent decrementing a 0 refcount in unblock_hpd_pin(). Cc: Jani Nikula <jani.nikula@intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Imre Deak <imre.deak@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20250305114820.3523077-1-imre.deak@intel.com
2025-03-05 13:48:19 +02:00
void intel_hpd_block(struct intel_encoder *encoder);
void intel_hpd_unblock(struct intel_encoder *encoder);
void intel_hpd_clear_and_unblock(struct intel_encoder *encoder);
void intel_hpd_debugfs_register(struct intel_display *display);
void intel_hpd_enable_detection_work(struct intel_display *display);
void intel_hpd_disable_detection_work(struct intel_display *display);
bool intel_hpd_schedule_detection(struct intel_display *display);
#endif /* __INTEL_HOTPLUG_H__ */