Changeset c3d9aaf5 in mainline

Timestamp:

2025-02-03T15:52:08Z (16 hours ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

master

Children:

b1490d2

Parents:

a796812c

Message:

Determine when device (sub)tree is stable.

Devman will only return value when the entire device tree is stable.

Location:

uspace/srv/devman

Files:

• dev.c (modified) (3 diffs)
• dev.h (modified) (2 diffs)
• devman.h (modified) (3 diffs)
• devtree.c (modified) (2 diffs)
• devtree.h (modified) (2 diffs)
• driver.c (modified) (5 diffs)
• main.c (modified) (2 diffs)

uspace/srv/devman/dev.c

@@ -1 +1 @@
 /*
+ * Copyright (c) 2025 Jiri Svoboda
  * Copyright (c) 2010 Lenka Trochtova
  * All rights reserved.
@@ -50 +51 @@
         refcount_init(&dev->refcnt);
         list_initialize(&dev->functions);
+        fibril_mutex_initialize(&dev->state_lock);
+        fibril_condvar_initialize(&dev->state_cv);
         link_initialize(&dev->driver_devices);
 
@@ -87 +90 @@
         if (refcount_down(&dev->refcnt))
                 delete_dev_node(dev);
+}
+
+/** Wait until the device node enters stable state.
+ *
+ * @param dev Device node
+ */
+void dev_wait_stable(dev_node_t *dev)
+{
+        fibril_mutex_lock(&dev->state_lock);
+        while (dev->state == DEVICE_ATTACHING)
+                fibril_condvar_wait(&dev->state_cv, &dev->state_lock);
+        fibril_mutex_unlock(&dev->state_lock);
 }
 

uspace/srv/devman/dev.h

@@ -1 +1 @@
 /*
+ * Copyright (c) 2025 Jiri Svoboda
  * Copyright (c) 2010 Lenka Trochtova
- * Copyright (c) 2013 Jiri Svoboda
  * All rights reserved.
  *
@@ -41 +41 @@
 extern void dev_add_ref(dev_node_t *);
 extern void dev_del_ref(dev_node_t *);
+extern void dev_wait_stable(dev_node_t *);
 
 extern dev_node_t *find_dev_node_no_lock(dev_tree_t *tree,

uspace/srv/devman/devman.h

@@ -1 +1 @@
 /*
+ * Copyright (c) 2025 Jiri Svoboda
  * Copyright (c) 2010 Lenka Trochtova
- * Copyright (c) 2011 Jiri Svoboda
  * All rights reserved.
  *
@@ -105 +105 @@
 typedef enum {
         DEVICE_NOT_INITIALIZED = 0,
+        DEVICE_ATTACHING,
         DEVICE_USABLE,
         DEVICE_NOT_PRESENT,
@@ -129 +130 @@
         /** The state of the device. */
         device_state_t state;
+        /** Protect device state field */
+        fibril_mutex_t state_lock;
+        /** Signalled when device state changes */
+        fibril_condvar_t state_cv;
         /** Link to list of devices owned by driver (driver_t.devices) */
         link_t driver_devices;

uspace/srv/devman/devtree.c

@@ -1 +1 @@
 /*
+ * Copyright (c) 2025 Jiri Svoboda
  * Copyright (c) 2010 Lenka Trochtova
  * All rights reserved.
@@ -314 +315 @@
 }
 
+/** Wait for device tree to stabilize.
+ *
+ * Blocks until the entire device tree had a chance to finish attaching
+ * all devices.
+ *
+ * @param tree Device tree
+ */
+void dev_tree_wait_stable(dev_tree_t *tree)
+{
+        dev_wait_stable(tree->root_node->child);
+}
+
 /** @}
  */

uspace/srv/devman/devtree.h

@@ -1 +1 @@
 /*
+ * Copyright (c) 2025 Jiri Svoboda
  * Copyright (c) 2010 Lenka Trochtova
- * Copyright (c) 2013 Jiri Svoboda
  * All rights reserved.
  *
@@ -45 +45 @@
 extern bool insert_fun_node(dev_tree_t *, fun_node_t *, char *, dev_node_t *);
 extern void remove_fun_node(dev_tree_t *, fun_node_t *);
+extern void dev_tree_wait_stable(dev_tree_t *);
 
 #endif

uspace/srv/devman/driver.c

@@ -1 +1 @@
 /*
- * Copyright (c) 2018 Jiri Svoboda
+ * Copyright (c) 2025 Jiri Svoboda
  * Copyright (c) 2010 Lenka Trochtova
  * All rights reserved.
@@ -284 +284 @@
         dev->drv = drv;
         dev->passed_to_driver = false;
-        dev->state = DEVICE_NOT_INITIALIZED;
+        fibril_mutex_lock(&dev->state_lock);
+        dev->state = DEVICE_ATTACHING;
+        fibril_mutex_unlock(&dev->state_lock);
+        fibril_condvar_broadcast(&dev->state_cv);
         list_append(&dev->driver_devices, &drv->devices);
 
@@ -631 +634 @@
 void add_device(driver_t *drv, dev_node_t *dev, dev_tree_t *tree)
 {
+        link_t *link;
+        fun_node_t *fun;
+
         /*
          * We do not expect to have driver's mutex locked as we do not
@@ -664 +670 @@
                 async_wait_for(req, &rc);
         }
+
+        if (rc == EOK) {
+                log_msg(LOG_DEFAULT, LVL_DEBUG, "Device was added. Wait for "
+                    "child functions' devices to stabilize.");
+                fibril_rwlock_read_lock(&tree->rwlock);
+                link = list_first(&dev->functions);
+                while (link != NULL) {
+                        fun = list_get_instance(link, fun_node_t,
+                            dev_functions);
+
+                        if (fun->child != NULL) {
+                                log_msg(LOG_DEFAULT, LVL_DEBUG2, "Wait for "
+                                    "child device %p.", (void *)fun->child);
+                                fun_add_ref(fun);
+                                fibril_rwlock_read_unlock(&tree->rwlock);
+                                dev_wait_stable(fun->child);
+                                fibril_rwlock_read_lock(&tree->rwlock);
+                                fun_del_ref(fun);
+                        }
+
+                        link = list_next(link, &dev->functions);
+                }
+
+                fibril_rwlock_read_unlock(&tree->rwlock);
+                log_msg(LOG_DEFAULT, LVL_DEBUG,
+                    "Finished waiting for children.");
+        }
+
+        fibril_mutex_lock(&dev->state_lock);
 
         switch (rc) {
@@ -677 +712 @@
         }
 
+        fibril_mutex_unlock(&dev->state_lock);
+        fibril_condvar_broadcast(&dev->state_cv);
+
         dev->passed_to_driver = true;
 }

uspace/srv/devman/main.c

@@ -1 +1 @@
 /*
- * Copyright (c) 2023 Jiri Svoboda
+ * Copyright (c) 2025 Jiri Svoboda
  * Copyright (c) 2010 Lenka Trochtova
  * All rights reserved.
@@ -369 +369 @@
 
         printf("%s: Accepting connections.\n", NAME);
+        log_msg(LOG_DEFAULT, LVL_NOTE, "Wait for device tree to stabilize.");
+        dev_tree_wait_stable(&device_tree);
+        log_msg(LOG_DEFAULT, LVL_NOTE, "Device tree stable.");
         task_retval(0);
         async_manager();