| /* |
| * Copyright © 2015 Intel Corporation |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the "Software"), |
| * to deal in the Software without restriction, including without limitation |
| * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| * and/or sell copies of the Software, and to permit persons to whom the |
| * Software is furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice (including the next |
| * paragraph) shall be included in all copies or substantial portions of the |
| * Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| * IN THE SOFTWARE. |
| */ |
| |
| #include <linux/kernel.h> |
| |
| #include <drm/drmP.h> |
| #include <drm/i915_drm.h> |
| |
| #include "i915_drv.h" |
| #include "intel_drv.h" |
| |
| /** |
| * DOC: Hotplug |
| * |
| * Simply put, hotplug occurs when a display is connected to or disconnected |
| * from the system. However, there may be adapters and docking stations and |
| * Display Port short pulses and MST devices involved, complicating matters. |
| * |
| * Hotplug in i915 is handled in many different levels of abstraction. |
| * |
| * The platform dependent interrupt handling code in i915_irq.c enables, |
| * disables, and does preliminary handling of the interrupts. The interrupt |
| * handlers gather the hotplug detect (HPD) information from relevant registers |
| * into a platform independent mask of hotplug pins that have fired. |
| * |
| * The platform independent interrupt handler intel_hpd_irq_handler() in |
| * intel_hotplug.c does hotplug irq storm detection and mitigation, and passes |
| * further processing to appropriate bottom halves (Display Port specific and |
| * regular hotplug). |
| * |
| * The Display Port work function i915_digport_work_func() calls into |
| * intel_dp_hpd_pulse() via hooks, which handles DP short pulses and DP MST long |
| * pulses, with failures and non-MST long pulses triggering regular hotplug |
| * processing on the connector. |
| * |
| * The regular hotplug work function i915_hotplug_work_func() calls connector |
| * detect hooks, and, if connector status changes, triggers sending of hotplug |
| * uevent to userspace via drm_kms_helper_hotplug_event(). |
| * |
| * Finally, the userspace is responsible for triggering a modeset upon receiving |
| * the hotplug uevent, disabling or enabling the crtc as needed. |
| * |
| * The hotplug interrupt storm detection and mitigation code keeps track of the |
| * number of interrupts per hotplug pin per a period of time, and if the number |
| * of interrupts exceeds a certain threshold, the interrupt is disabled for a |
| * while before being re-enabled. The intention is to mitigate issues raising |
| * from broken hardware triggering massive amounts of interrupts and grinding |
| * the system to a halt. |
| * |
| * Current implementation expects that hotplug interrupt storm will not be |
| * seen when display port sink is connected, hence on platforms whose DP |
| * callback is handled by i915_digport_work_func reenabling of hpd is not |
| * performed (it was never expected to be disabled in the first place ;) ) |
| * this is specific to DP sinks handled by this routine and any other display |
| * such as HDMI or DVI enabled on the same port will have proper logic since |
| * it will use i915_hotplug_work_func where this logic is handled. |
| */ |
| |
| bool intel_hpd_pin_to_port(enum hpd_pin pin, enum port *port) |
| { |
| switch (pin) { |
| case HPD_PORT_A: |
| *port = PORT_A; |
| return true; |
| case HPD_PORT_B: |
| *port = PORT_B; |
| return true; |
| case HPD_PORT_C: |
| *port = PORT_C; |
| return true; |
| case HPD_PORT_D: |
| *port = PORT_D; |
| return true; |
| case HPD_PORT_E: |
| *port = PORT_E; |
| return true; |
| default: |
| return false; /* no hpd */ |
| } |
| } |
| |
| #define HPD_STORM_DETECT_PERIOD 1000 |
| #define HPD_STORM_THRESHOLD 5 |
| #define HPD_STORM_REENABLE_DELAY (2 * 60 * 1000) |
| |
| /** |
| * intel_hpd_irq_storm_detect - gather stats and detect HPD irq storm on a pin |
| * @dev_priv: private driver data pointer |
| * @pin: the pin to gather stats on |
| * |
| * Gather stats about HPD irqs from the specified @pin, and detect irq |
| * storms. Only the pin specific stats and state are changed, the caller is |
| * responsible for further action. |
| * |
| * @HPD_STORM_THRESHOLD irqs are allowed within @HPD_STORM_DETECT_PERIOD ms, |
| * otherwise it's considered an irq storm, and the irq state is set to |
| * @HPD_MARK_DISABLED. |
| * |
| * Return true if an irq storm was detected on @pin. |
| */ |
| static bool intel_hpd_irq_storm_detect(struct drm_i915_private *dev_priv, |
| enum hpd_pin pin) |
| { |
| unsigned long start = dev_priv->hotplug.stats[pin].last_jiffies; |
| unsigned long end = start + msecs_to_jiffies(HPD_STORM_DETECT_PERIOD); |
| bool storm = false; |
| |
| if (!time_in_range(jiffies, start, end)) { |
| dev_priv->hotplug.stats[pin].last_jiffies = jiffies; |
| dev_priv->hotplug.stats[pin].count = 0; |
| DRM_DEBUG_KMS("Received HPD interrupt on PIN %d - cnt: 0\n", pin); |
| } else if (dev_priv->hotplug.stats[pin].count > HPD_STORM_THRESHOLD) { |
| dev_priv->hotplug.stats[pin].state = HPD_MARK_DISABLED; |
| DRM_DEBUG_KMS("HPD interrupt storm detected on PIN %d\n", pin); |
| storm = true; |
| } else { |
| dev_priv->hotplug.stats[pin].count++; |
| DRM_DEBUG_KMS("Received HPD interrupt on PIN %d - cnt: %d\n", pin, |
| dev_priv->hotplug.stats[pin].count); |
| } |
| |
| return storm; |
| } |
| |
| static void intel_hpd_irq_storm_disable(struct drm_i915_private *dev_priv) |
| { |
| struct drm_device *dev = &dev_priv->drm; |
| struct drm_mode_config *mode_config = &dev->mode_config; |
| struct intel_connector *intel_connector; |
| struct intel_encoder *intel_encoder; |
| struct drm_connector *connector; |
| enum hpd_pin pin; |
| bool hpd_disabled = false; |
| |
| assert_spin_locked(&dev_priv->irq_lock); |
| |
| list_for_each_entry(connector, &mode_config->connector_list, head) { |
| if (connector->polled != DRM_CONNECTOR_POLL_HPD) |
| continue; |
| |
| intel_connector = to_intel_connector(connector); |
| intel_encoder = intel_connector->encoder; |
| if (!intel_encoder) |
| continue; |
| |
| pin = intel_encoder->hpd_pin; |
| if (pin == HPD_NONE || |
| dev_priv->hotplug.stats[pin].state != HPD_MARK_DISABLED) |
| continue; |
| |
| DRM_INFO("HPD interrupt storm detected on connector %s: " |
| "switching from hotplug detection to polling\n", |
| connector->name); |
| |
| dev_priv->hotplug.stats[pin].state = HPD_DISABLED; |
| connector->polled = DRM_CONNECTOR_POLL_CONNECT |
| | DRM_CONNECTOR_POLL_DISCONNECT; |
| hpd_disabled = true; |
| } |
| |
| /* Enable polling and queue hotplug re-enabling. */ |
| if (hpd_disabled) { |
| drm_kms_helper_poll_enable_locked(dev); |
| mod_delayed_work(system_wq, &dev_priv->hotplug.reenable_work, |
| msecs_to_jiffies(HPD_STORM_REENABLE_DELAY)); |
| } |
| } |
| |
| static void intel_hpd_irq_storm_reenable_work(struct work_struct *work) |
| { |
| struct drm_i915_private *dev_priv = |
| container_of(work, typeof(*dev_priv), |
| hotplug.reenable_work.work); |
| struct drm_device *dev = &dev_priv->drm; |
| struct drm_mode_config *mode_config = &dev->mode_config; |
| int i; |
| |
| intel_runtime_pm_get(dev_priv); |
| |
| spin_lock_irq(&dev_priv->irq_lock); |
| for_each_hpd_pin(i) { |
| struct drm_connector *connector; |
| |
| if (dev_priv->hotplug.stats[i].state != HPD_DISABLED) |
| continue; |
| |
| dev_priv->hotplug.stats[i].state = HPD_ENABLED; |
| |
| list_for_each_entry(connector, &mode_config->connector_list, head) { |
| struct intel_connector *intel_connector = to_intel_connector(connector); |
| |
| if (intel_connector->encoder->hpd_pin == i) { |
| if (connector->polled != intel_connector->polled) |
| DRM_DEBUG_DRIVER("Reenabling HPD on connector %s\n", |
| connector->name); |
| connector->polled = intel_connector->polled; |
| if (!connector->polled) |
| connector->polled = DRM_CONNECTOR_POLL_HPD; |
| } |
| } |
| } |
| if (dev_priv->display.hpd_irq_setup) |
| dev_priv->display.hpd_irq_setup(dev_priv); |
| spin_unlock_irq(&dev_priv->irq_lock); |
| |
| intel_runtime_pm_put(dev_priv); |
| } |
| |
| static bool intel_hpd_irq_event(struct drm_device *dev, |
| struct drm_connector *connector) |
| { |
| enum drm_connector_status old_status; |
| |
| WARN_ON(!mutex_is_locked(&dev->mode_config.mutex)); |
| old_status = connector->status; |
| |
| connector->status = connector->funcs->detect(connector, false); |
| if (old_status == connector->status) |
| return false; |
| |
| DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n", |
| connector->base.id, |
| connector->name, |
| drm_get_connector_status_name(old_status), |
| drm_get_connector_status_name(connector->status)); |
| |
| return true; |
| } |
| |
| static void i915_digport_work_func(struct work_struct *work) |
| { |
| struct drm_i915_private *dev_priv = |
| container_of(work, struct drm_i915_private, hotplug.dig_port_work); |
| u32 long_port_mask, short_port_mask; |
| struct intel_digital_port *intel_dig_port; |
| int i; |
| u32 old_bits = 0; |
| |
| spin_lock_irq(&dev_priv->irq_lock); |
| long_port_mask = dev_priv->hotplug.long_port_mask; |
| dev_priv->hotplug.long_port_mask = 0; |
| short_port_mask = dev_priv->hotplug.short_port_mask; |
| dev_priv->hotplug.short_port_mask = 0; |
| spin_unlock_irq(&dev_priv->irq_lock); |
| |
| for (i = 0; i < I915_MAX_PORTS; i++) { |
| bool valid = false; |
| bool long_hpd = false; |
| intel_dig_port = dev_priv->hotplug.irq_port[i]; |
| if (!intel_dig_port || !intel_dig_port->hpd_pulse) |
| continue; |
| |
| if (long_port_mask & (1 << i)) { |
| valid = true; |
| long_hpd = true; |
| } else if (short_port_mask & (1 << i)) |
| valid = true; |
| |
| if (valid) { |
| enum irqreturn ret; |
| |
| ret = intel_dig_port->hpd_pulse(intel_dig_port, long_hpd); |
| if (ret == IRQ_NONE) { |
| /* fall back to old school hpd */ |
| old_bits |= (1 << intel_dig_port->base.hpd_pin); |
| } |
| } |
| } |
| |
| if (old_bits) { |
| spin_lock_irq(&dev_priv->irq_lock); |
| dev_priv->hotplug.event_bits |= old_bits; |
| spin_unlock_irq(&dev_priv->irq_lock); |
| schedule_work(&dev_priv->hotplug.hotplug_work); |
| } |
| } |
| |
| /* |
| * Handle hotplug events outside the interrupt handler proper. |
| */ |
| static void i915_hotplug_work_func(struct work_struct *work) |
| { |
| struct drm_i915_private *dev_priv = |
| container_of(work, struct drm_i915_private, hotplug.hotplug_work); |
| struct drm_device *dev = &dev_priv->drm; |
| struct drm_mode_config *mode_config = &dev->mode_config; |
| struct intel_connector *intel_connector; |
| struct intel_encoder *intel_encoder; |
| struct drm_connector *connector; |
| bool changed = false; |
| u32 hpd_event_bits; |
| |
| mutex_lock(&mode_config->mutex); |
| DRM_DEBUG_KMS("running encoder hotplug functions\n"); |
| |
| spin_lock_irq(&dev_priv->irq_lock); |
| |
| hpd_event_bits = dev_priv->hotplug.event_bits; |
| dev_priv->hotplug.event_bits = 0; |
| |
| /* Disable hotplug on connectors that hit an irq storm. */ |
| intel_hpd_irq_storm_disable(dev_priv); |
| |
| spin_unlock_irq(&dev_priv->irq_lock); |
| |
| list_for_each_entry(connector, &mode_config->connector_list, head) { |
| intel_connector = to_intel_connector(connector); |
| if (!intel_connector->encoder) |
| continue; |
| intel_encoder = intel_connector->encoder; |
| if (hpd_event_bits & (1 << intel_encoder->hpd_pin)) { |
| DRM_DEBUG_KMS("Connector %s (pin %i) received hotplug event.\n", |
| connector->name, intel_encoder->hpd_pin); |
| if (intel_encoder->hot_plug) |
| intel_encoder->hot_plug(intel_encoder); |
| if (intel_hpd_irq_event(dev, connector)) |
| changed = true; |
| } |
| } |
| mutex_unlock(&mode_config->mutex); |
| |
| if (changed) |
| drm_kms_helper_hotplug_event(dev); |
| } |
| |
| |
| /** |
| * intel_hpd_irq_handler - main hotplug irq handler |
| * @dev_priv: drm_i915_private |
| * @pin_mask: a mask of hpd pins that have triggered the irq |
| * @long_mask: a mask of hpd pins that may be long hpd pulses |
| * |
| * This is the main hotplug irq handler for all platforms. The platform specific |
| * irq handlers call the platform specific hotplug irq handlers, which read and |
| * decode the appropriate registers into bitmasks about hpd pins that have |
| * triggered (@pin_mask), and which of those pins may be long pulses |
| * (@long_mask). The @long_mask is ignored if the port corresponding to the pin |
| * is not a digital port. |
| * |
| * Here, we do hotplug irq storm detection and mitigation, and pass further |
| * processing to appropriate bottom halves. |
| */ |
| void intel_hpd_irq_handler(struct drm_i915_private *dev_priv, |
| u32 pin_mask, u32 long_mask) |
| { |
| int i; |
| enum port port; |
| bool storm_detected = false; |
| bool queue_dig = false, queue_hp = false; |
| bool is_dig_port; |
| |
| if (!pin_mask) |
| return; |
| |
| spin_lock(&dev_priv->irq_lock); |
| for_each_hpd_pin(i) { |
| if (!(BIT(i) & pin_mask)) |
| continue; |
| |
| is_dig_port = intel_hpd_pin_to_port(i, &port) && |
| dev_priv->hotplug.irq_port[port]; |
| |
| if (is_dig_port) { |
| bool long_hpd = long_mask & BIT(i); |
| |
| DRM_DEBUG_DRIVER("digital hpd port %c - %s\n", port_name(port), |
| long_hpd ? "long" : "short"); |
| /* |
| * For long HPD pulses we want to have the digital queue happen, |
| * but we still want HPD storm detection to function. |
| */ |
| queue_dig = true; |
| if (long_hpd) { |
| dev_priv->hotplug.long_port_mask |= (1 << port); |
| } else { |
| /* for short HPD just trigger the digital queue */ |
| dev_priv->hotplug.short_port_mask |= (1 << port); |
| continue; |
| } |
| } |
| |
| if (dev_priv->hotplug.stats[i].state == HPD_DISABLED) { |
| /* |
| * On GMCH platforms the interrupt mask bits only |
| * prevent irq generation, not the setting of the |
| * hotplug bits itself. So only WARN about unexpected |
| * interrupts on saner platforms. |
| */ |
| WARN_ONCE(!HAS_GMCH_DISPLAY(dev_priv), |
| "Received HPD interrupt on pin %d although disabled\n", i); |
| continue; |
| } |
| |
| if (dev_priv->hotplug.stats[i].state != HPD_ENABLED) |
| continue; |
| |
| if (!is_dig_port) { |
| dev_priv->hotplug.event_bits |= BIT(i); |
| queue_hp = true; |
| } |
| |
| if (intel_hpd_irq_storm_detect(dev_priv, i)) { |
| dev_priv->hotplug.event_bits &= ~BIT(i); |
| storm_detected = true; |
| } |
| } |
| |
| if (storm_detected) |
| dev_priv->display.hpd_irq_setup(dev_priv); |
| spin_unlock(&dev_priv->irq_lock); |
| |
| /* |
| * Our hotplug handler can grab modeset locks (by calling down into the |
| * fb helpers). Hence it must not be run on our own dev-priv->wq work |
| * queue for otherwise the flush_work in the pageflip code will |
| * deadlock. |
| */ |
| if (queue_dig) |
| queue_work(dev_priv->hotplug.dp_wq, &dev_priv->hotplug.dig_port_work); |
| if (queue_hp) |
| schedule_work(&dev_priv->hotplug.hotplug_work); |
| } |
| |
| /** |
| * intel_hpd_init - initializes and enables hpd support |
| * @dev_priv: i915 device instance |
| * |
| * This function enables the hotplug support. It requires that interrupts have |
| * already been enabled with intel_irq_init_hw(). From this point on hotplug and |
| * poll request can run concurrently to other code, so locking rules must be |
| * obeyed. |
| * |
| * This is a separate step from interrupt enabling to simplify the locking rules |
| * in the driver load and resume code. |
| */ |
| void intel_hpd_init(struct drm_i915_private *dev_priv) |
| { |
| struct drm_device *dev = &dev_priv->drm; |
| struct drm_mode_config *mode_config = &dev->mode_config; |
| struct drm_connector *connector; |
| int i; |
| |
| for_each_hpd_pin(i) { |
| dev_priv->hotplug.stats[i].count = 0; |
| dev_priv->hotplug.stats[i].state = HPD_ENABLED; |
| } |
| list_for_each_entry(connector, &mode_config->connector_list, head) { |
| struct intel_connector *intel_connector = to_intel_connector(connector); |
| connector->polled = intel_connector->polled; |
| |
| /* MST has a dynamic intel_connector->encoder and it's reprobing |
| * is all handled by the MST helpers. */ |
| if (intel_connector->mst_port) |
| continue; |
| |
| if (!connector->polled && I915_HAS_HOTPLUG(dev) && |
| intel_connector->encoder->hpd_pin > HPD_NONE) |
| connector->polled = DRM_CONNECTOR_POLL_HPD; |
| } |
| |
| /* |
| * Interrupt setup is already guaranteed to be single-threaded, this is |
| * just to make the assert_spin_locked checks happy. |
| */ |
| spin_lock_irq(&dev_priv->irq_lock); |
| if (dev_priv->display.hpd_irq_setup) |
| dev_priv->display.hpd_irq_setup(dev_priv); |
| spin_unlock_irq(&dev_priv->irq_lock); |
| } |
| |
| void intel_hpd_init_work(struct drm_i915_private *dev_priv) |
| { |
| INIT_WORK(&dev_priv->hotplug.hotplug_work, i915_hotplug_work_func); |
| INIT_WORK(&dev_priv->hotplug.dig_port_work, i915_digport_work_func); |
| INIT_DELAYED_WORK(&dev_priv->hotplug.reenable_work, |
| intel_hpd_irq_storm_reenable_work); |
| } |
| |
| void intel_hpd_cancel_work(struct drm_i915_private *dev_priv) |
| { |
| spin_lock_irq(&dev_priv->irq_lock); |
| |
| dev_priv->hotplug.long_port_mask = 0; |
| dev_priv->hotplug.short_port_mask = 0; |
| dev_priv->hotplug.event_bits = 0; |
| |
| spin_unlock_irq(&dev_priv->irq_lock); |
| |
| cancel_work_sync(&dev_priv->hotplug.dig_port_work); |
| cancel_work_sync(&dev_priv->hotplug.hotplug_work); |
| cancel_delayed_work_sync(&dev_priv->hotplug.reenable_work); |
| } |