Merge tag 'topic/mst-suspend-resume-reprobe-2019-10-29-2' of git://anongit.freedesktop.org/drm/drm-misc into drm-next

UAPI Changes:

Cross-subsystem Changes:

Core Changes:
* Handle UP requests asynchronously in the DP MST helpers, fixing
  hotplug notifications and allowing us to implement suspend/resume
  reprobing
* Add basic suspend/resume reprobing to the DP MST helpers
* Improve locking for link address reprobing and connection status
  request handling in the DP MST helpers
* Miscellaneous refactoring in the DP MST helpers
* Add a Kconfig option to the DP MST helpers to enable tracking of
  gets/puts for topology references for debugging purposes

Driver Changes:
* nouveau: Resume hotplug interrupts earlier, so that sideband
  messages may be transmitted during resume and thus allow
  suspend/resume reprobing for DP MST to work
* nouveau: Avoid grabbing runtime PM references when handling short DP
  pulses, so that handling sideband messages in resume codepaths with the
  DP MST helpers doesn't deadlock us
* i915, nouveau, amdgpu, radeon: Use detect_ctx for probing MST
  connectors, so that we can grab the topology manager's atomic lock

Note: there's some amdgpu patches that I didn't realize were pushed
upstream already when creating this topic branch. When they fail to
apply, you can just ignore and skip them.

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/a74c6446bc960190d195a751cb6d8a00a98f3974.camel@redhat.com

1 files changed, 137 insertions, 23 deletions

diff --git a/include/drm/drm_dp_mst_helper.h b/include/drm/drm_dp_mst_helper.h
index 4a25e0577ae0..d5fc90b30487 100644
--- a/include/drm/drm_dp_mst_helper.h
+++ b/include/drm/drm_dp_mst_helper.h
@@ -26,6 +26,26 @@
 #include <drm/drm_dp_helper.h>
 #include <drm/drm_atomic.h>
 
+#if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
+#include <linux/stackdepot.h>
+#include <linux/timekeeping.h>
+
+enum drm_dp_mst_topology_ref_type {
+	DRM_DP_MST_TOPOLOGY_REF_GET,
+	DRM_DP_MST_TOPOLOGY_REF_PUT,
+};
+
+struct drm_dp_mst_topology_ref_history {
+	struct drm_dp_mst_topology_ref_entry {
+		enum drm_dp_mst_topology_ref_type type;
+		int count;
+		ktime_t ts_nsec;
+		depot_stack_handle_t backtrace;
+	} *entries;
+	int len;
+};
+#endif /* IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS) */
+
 struct drm_dp_mst_branch;
 
 /**
@@ -45,21 +65,31 @@ struct drm_dp_vcpi {
 /**
  * struct drm_dp_mst_port - MST port
  * @port_num: port number
- * @input: if this port is an input port.
- * @mcs: message capability status - DP 1.2 spec.
- * @ddps: DisplayPort Device Plug Status - DP 1.2
- * @pdt: Peer Device Type
- * @ldps: Legacy Device Plug Status
- * @dpcd_rev: DPCD revision of device on this port
- * @num_sdp_streams: Number of simultaneous streams
- * @num_sdp_stream_sinks: Number of stream sinks
- * @available_pbn: Available bandwidth for this port.
+ * @input: if this port is an input port. Protected by
+ * &drm_dp_mst_topology_mgr.base.lock.
+ * @mcs: message capability status - DP 1.2 spec. Protected by
+ * &drm_dp_mst_topology_mgr.base.lock.
+ * @ddps: DisplayPort Device Plug Status - DP 1.2. Protected by
+ * &drm_dp_mst_topology_mgr.base.lock.
+ * @pdt: Peer Device Type. Protected by
+ * &drm_dp_mst_topology_mgr.base.lock.
+ * @ldps: Legacy Device Plug Status. Protected by
+ * &drm_dp_mst_topology_mgr.base.lock.
+ * @dpcd_rev: DPCD revision of device on this port. Protected by
+ * &drm_dp_mst_topology_mgr.base.lock.
+ * @num_sdp_streams: Number of simultaneous streams. Protected by
+ * &drm_dp_mst_topology_mgr.base.lock.
+ * @num_sdp_stream_sinks: Number of stream sinks. Protected by
+ * &drm_dp_mst_topology_mgr.base.lock.
+ * @available_pbn: Available bandwidth for this port. Protected by
+ * &drm_dp_mst_topology_mgr.base.lock.
  * @next: link to next port on this branch device
- * @mstb: branch device attach below this port
- * @aux: i2c aux transport to talk to device connected to this port.
+ * @aux: i2c aux transport to talk to device connected to this port, protected
+ * by &drm_dp_mst_topology_mgr.base.lock.
  * @parent: branch device parent of this port
  * @vcpi: Virtual Channel Payload info for this port.
- * @connector: DRM connector this port is connected to.
+ * @connector: DRM connector this port is connected to. Protected by
+ * &drm_dp_mst_topology_mgr.base.lock.
  * @mgr: topology manager this port lives under.
  *
  * This structure represents an MST port endpoint on a device somewhere
@@ -79,6 +109,14 @@ struct drm_dp_mst_port {
 	 */
 	struct kref malloc_kref;
 
+#if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
+	/**
+	 * @topology_ref_history: A history of each topology
+	 * reference/dereference. See CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS.
+	 */
+	struct drm_dp_mst_topology_ref_history topology_ref_history;
+#endif
+
 	u8 port_num;
 	bool input;
 	bool mcs;
@@ -90,7 +128,17 @@ struct drm_dp_mst_port {
 	u8 num_sdp_stream_sinks;
 	uint16_t available_pbn;
 	struct list_head next;
-	struct drm_dp_mst_branch *mstb; /* pointer to an mstb if this port has one */
+	/**
+	 * @mstb: the branch device connected to this port, if there is one.
+	 * This should be considered protected for reading by
+	 * &drm_dp_mst_topology_mgr.lock. There are two exceptions to this:
+	 * &drm_dp_mst_topology_mgr.up_req_work and
+	 * &drm_dp_mst_topology_mgr.work, which do not grab
+	 * &drm_dp_mst_topology_mgr.lock during reads but are the only
+	 * updaters of this list and are protected from writing concurrently
+	 * by &drm_dp_mst_topology_mgr.probe_lock.
+	 */
+	struct drm_dp_mst_branch *mstb;
 	struct drm_dp_aux aux; /* i2c bus for this port? */
 	struct drm_dp_mst_branch *parent;
 
@@ -116,7 +164,6 @@ struct drm_dp_mst_port {
  * @lct: Link count total to talk to this branch device.
  * @num_ports: number of ports on the branch.
  * @msg_slots: one bit per transmitted msg slot.
- * @ports: linked list of ports on this branch.
  * @port_parent: pointer to the port parent, NULL if toplevel.
  * @mgr: topology manager for this branch device.
  * @tx_slots: transmission slots for this device.
@@ -143,11 +190,35 @@ struct drm_dp_mst_branch {
 	 */
 	struct kref malloc_kref;
 
+#if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
+	/**
+	 * @topology_ref_history: A history of each topology
+	 * reference/dereference. See CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS.
+	 */
+	struct drm_dp_mst_topology_ref_history topology_ref_history;
+#endif
+
+	/**
+	 * @destroy_next: linked-list entry used by
+	 * drm_dp_delayed_destroy_work()
+	 */
+	struct list_head destroy_next;
+
 	u8 rad[8];
 	u8 lct;
 	int num_ports;
 
 	int msg_slots;
+	/**
+	 * @ports: the list of ports on this branch device. This should be
+	 * considered protected for reading by &drm_dp_mst_topology_mgr.lock.
+	 * There are two exceptions to this:
+	 * &drm_dp_mst_topology_mgr.up_req_work and
+	 * &drm_dp_mst_topology_mgr.work, which do not grab
+	 * &drm_dp_mst_topology_mgr.lock during reads but are the only
+	 * updaters of this list and are protected from updating the list
+	 * concurrently by @drm_dp_mst_topology_mgr.probe_lock
+	 */
 	struct list_head ports;
 
 	/* list of tx ops queue for this port */
@@ -495,6 +566,13 @@ struct drm_dp_mst_topology_mgr {
 	struct mutex lock;
 
 	/**
+	 * @probe_lock: Prevents @work and @up_req_work, the only writers of
+	 * &drm_dp_mst_port.mstb and &drm_dp_mst_branch.ports, from racing
+	 * while they update the topology.
+	 */
+	struct mutex probe_lock;
+
+	/**
 	 * @mst_state: If this manager is enabled for an MST capable port. False
 	 * if no MST sink/branch devices is connected.
 	 */
@@ -571,18 +649,49 @@ struct drm_dp_mst_topology_mgr {
 	struct work_struct tx_work;
 
 	/**
-	 * @destroy_connector_list: List of to be destroyed connectors.
+	 * @destroy_port_list: List of to be destroyed connectors.
+	 */
+	struct list_head destroy_port_list;
+	/**
+	 * @destroy_branch_device_list: List of to be destroyed branch
+	 * devices.
+	 */
+	struct list_head destroy_branch_device_list;
+	/**
+	 * @delayed_destroy_lock: Protects @destroy_port_list and
+	 * @destroy_branch_device_list.
+	 */
+	struct mutex delayed_destroy_lock;
+	/**
+	 * @delayed_destroy_work: Work item to destroy MST port and branch
+	 * devices, needed to avoid locking inversion.
+	 */
+	struct work_struct delayed_destroy_work;
+
+	/**
+	 * @up_req_list: List of pending up requests from the topology that
+	 * need to be processed, in chronological order.
 	 */
-	struct list_head destroy_connector_list;
+	struct list_head up_req_list;
 	/**
-	 * @destroy_connector_lock: Protects @connector_list.
+	 * @up_req_lock: Protects @up_req_list
 	 */
-	struct mutex destroy_connector_lock;
+	struct mutex up_req_lock;
 	/**
-	 * @destroy_connector_work: Work item to destroy connectors. Needed to
-	 * avoid locking inversion.
+	 * @up_req_work: Work item to process up requests received from the
+	 * topology. Needed to avoid blocking hotplug handling and sideband
+	 * transmissions.
 	 */
-	struct work_struct destroy_connector_work;
+	struct work_struct up_req_work;
+
+#if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
+	/**
+	 * @topology_ref_history_lock: protects
+	 * &drm_dp_mst_port.topology_ref_history and
+	 * &drm_dp_mst_branch.topology_ref_history.
+	 */
+	struct mutex topology_ref_history_lock;
+#endif
 };
 
 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
@@ -599,7 +708,11 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms
 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled);
 
 
-enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);
+int
+drm_dp_mst_detect_port(struct drm_connector *connector,
+		       struct drm_modeset_acquire_ctx *ctx,
+		       struct drm_dp_mst_topology_mgr *mgr,
+		       struct drm_dp_mst_port *port);
 
 bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr,
 					struct drm_dp_mst_port *port);
@@ -638,7 +751,8 @@ void drm_dp_mst_dump_topology(struct seq_file *m,
 
 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr);
 int __must_check
-drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr);
+drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr,
+			       bool sync);
 
 ssize_t drm_dp_mst_dpcd_read(struct drm_dp_aux *aux,
 			     unsigned int offset, void *buffer, size_t size);