w1: async netlink, search, fixes, and improvements

index 40788c9..73705af 100644
@@ -54,28 +54,29 @@ static void w1_send_slave(struct w1_master *dev, u64 rn)
 	struct w1_netlink_msg *hdr = (struct w1_netlink_msg *)(msg + 1);
 	struct w1_netlink_cmd *cmd = (struct w1_netlink_cmd *)(hdr + 1);
 	int avail;
+	u64 *data;
 
 	/* update kernel slave list */
 	w1_slave_found(dev, rn);
 
 	avail = dev->priv_size - cmd->len;
 
-	if (avail > 8) {
-		u64 *data = (void *)(cmd + 1) + cmd->len;
+	if (avail < 8) {
+		msg->ack++;
+		cn_netlink_send(msg, 0, GFP_KERNEL);
 
-		*data = rn;
-		cmd->len += 8;
-		hdr->len += 8;
-		msg->len += 8;
-		return;
+		msg->len = sizeof(struct w1_netlink_msg) +
+			sizeof(struct w1_netlink_cmd);
+		hdr->len = sizeof(struct w1_netlink_cmd);
+		cmd->len = 0;
 	}
 
-	msg->ack++;
-	cn_netlink_send(msg, 0, GFP_KERNEL);
+	data = (void *)(cmd + 1) + cmd->len;
 
-	msg->len = sizeof(struct w1_netlink_msg) + sizeof(struct w1_netlink_cmd);
-	hdr->len = sizeof(struct w1_netlink_cmd);
-	cmd->len = 0;
+	*data = rn;
+	cmd->len += 8;
+	hdr->len += 8;
+	msg->len += 8;
 }
 
 static int w1_process_search_command(struct w1_master *dev, struct cn_msg *msg,

index 66efa96..67b6d5f 100644
@@ -960,8 +960,7 @@ void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb
 			tmp64 = (triplet_ret >> 2);
 			rn |= (tmp64 << i);
 
-			/* ensure we're called from kthread and not by netlink callback */
-			if (!dev->priv && kthread_should_stop()) {
+			if (test_bit(W1_ABORT_SEARCH, &dev->flags)) {
 				mutex_unlock(&dev->bus_mutex);
 				dev_dbg(&dev->dev, "Abort w1_search\n");
 				return;

index ca8081a..bc329d2 100644
@@ -155,6 +155,14 @@ struct w1_bus_master
 		u8, w1_slave_found_callback);
 };
 
+/**
+ * enum w1_master_flags - bitfields used in w1_master.flags
+ * @W1_ABORT_SEARCH: abort searching early on shutdown
+ */
+enum w1_master_flags {
+	W1_ABORT_SEARCH = 0,
+};
+
 struct w1_master
 {
 	struct list_head	w1_master_entry;

@@ -178,6 +186,8 @@ struct w1_master
 	/** 5V strong pullup duration in milliseconds, zero disabled. */
 	int			pullup_duration;
 
+	long			flags;
+
 	struct task_struct	*thread;
 	struct mutex		mutex;
 	struct mutex		bus_mutex;

index 590bd8a..423f3c2 100644
@@ -172,6 +172,7 @@ int w1_add_master_device(struct w1_bus_master *master)
 
 #if 0 /* Thread cleanup code, not required currently. */
 err_out_kill_thread:
+	set_bit(W1_ABORT_SEARCH, &dev->flags);
 	kthread_stop(dev->thread);
 #endif
 err_out_rm_attr:

@@ -187,6 +188,7 @@ void __w1_remove_master_device(struct w1_master *dev)
 	struct w1_netlink_msg msg;
 	struct w1_slave *sl, *sln;
 
+	set_bit(W1_ABORT_SEARCH, &dev->flags);
 	kthread_stop(dev->thread);
 
 	mutex_lock(&w1_mlock);

index 67b6d5f..92766a9 100644
@@ -243,7 +243,9 @@ static ssize_t w1_master_attribute_store_search(struct device * dev,
 	mutex_lock(&md->mutex);
 	md->search_count = tmp;
 	mutex_unlock(&md->mutex);
-	wake_up_process(md->thread);
+	/* Only wake if it is going to be searching. */
+	if (tmp)
+		wake_up_process(md->thread);
 
 	return count;
 }

index 92766a9..34ffdc6 100644
@@ -46,7 +46,7 @@ MODULE_AUTHOR("Evgeniy Polyakov <[email protected]>");
 MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol.");
 
 static int w1_timeout = 10;
-int w1_max_slave_count = 10;
+int w1_max_slave_count = 64;
 int w1_max_slave_ttl = 10;
 
 module_param_named(timeout, w1_timeout, int, 0);

@@ -316,6 +316,24 @@ static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct devic
 	return count;
 }
 
+static ssize_t w1_master_attribute_store_max_slave_count(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	long tmp;
+	struct w1_master *md = dev_to_w1_master(dev);
+
+	if (kstrtol(buf, 0, &tmp) == -EINVAL || tmp < 1)
+		return -EINVAL;
+
+	mutex_lock(&md->mutex);
+	md->max_slave_count = tmp;
+	/* allow each time the max_slave_count is updated */
+	clear_bit(W1_WARN_MAX_COUNT, &md->flags);
+	mutex_unlock(&md->mutex);
+
+	return count;
+}
+
 static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	struct w1_master *md = dev_to_w1_master(dev);

@@ -518,7 +536,7 @@ static ssize_t w1_master_attribute_store_remove(struct device *dev,
 static W1_MASTER_ATTR_RO(name, S_IRUGO);
 static W1_MASTER_ATTR_RO(slaves, S_IRUGO);
 static W1_MASTER_ATTR_RO(slave_count, S_IRUGO);
-static W1_MASTER_ATTR_RO(max_slave_count, S_IRUGO);
+static W1_MASTER_ATTR_RW(max_slave_count, S_IRUGO | S_IWUSR | S_IWGRP);
 static W1_MASTER_ATTR_RO(attempts, S_IRUGO);
 static W1_MASTER_ATTR_RO(timeout, S_IRUGO);
 static W1_MASTER_ATTR_RO(pointer, S_IRUGO);

@@ -976,6 +994,14 @@ void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb
 			desc_bit = last_zero;
 			cb(dev, rn);
 		}
+
+		if (!last_device && slave_count == dev->max_slave_count &&
+			!test_bit(W1_WARN_MAX_COUNT, &dev->flags)) {
+			dev_info(&dev->dev, "%s: max_slave_count %d reached, "
+				"additional sensors ignored\n", __func__,
+				dev->max_slave_count);
+			set_bit(W1_WARN_MAX_COUNT, &dev->flags);
+		}
 	}
 }
 

index bc329d2..bd10b3c 100644
@@ -158,9 +158,11 @@ struct w1_bus_master
 /**
  * enum w1_master_flags - bitfields used in w1_master.flags
  * @W1_ABORT_SEARCH: abort searching early on shutdown
+ * @W1_WARN_MAX_COUNT: limit warning when the maximum count is reached
  */
 enum w1_master_flags {
 	W1_ABORT_SEARCH = 0,
+	W1_WARN_MAX_COUNT = 1,
 };
 
 struct w1_master

index 34ffdc6..4c89f85 100644
@@ -918,7 +918,8 @@ void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb
 	u8  triplet_ret = 0;
 
 	search_bit = 0;
-	rn = last_rn = 0;
+	rn = dev->search_id;
+	last_rn = 0;
 	last_device = 0;
 	last_zero = -1;
 

@@ -989,16 +990,27 @@ void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb
 		mutex_unlock(&dev->bus_mutex);
 
 		if ( (triplet_ret & 0x03) != 0x03 ) {
-			if ( (desc_bit == last_zero) || (last_zero < 0))
+			if ((desc_bit == last_zero) || (last_zero < 0)) {
 				last_device = 1;
+				dev->search_id = 0;
+			} else {
+				dev->search_id = rn;
+			}
 			desc_bit = last_zero;
 			cb(dev, rn);
 		}
 
 		if (!last_device && slave_count == dev->max_slave_count &&
 			!test_bit(W1_WARN_MAX_COUNT, &dev->flags)) {
+			/* Only max_slave_count will be scanned in a search,
+			 * but it will start where it left off next search
+			 * until all ids are identified and then it will start
+			 * over.  A continued search will report the previous
+			 * last id as the first id (provided it is still on the
+			 * bus).
+			 */
 			dev_info(&dev->dev, "%s: max_slave_count %d reached, "
-				"additional sensors ignored\n", __func__,
+				"will continue next search.\n", __func__,
 				dev->max_slave_count);
 			set_bit(W1_WARN_MAX_COUNT, &dev->flags);
 		}

index bd10b3c..80fbdf9 100644
@@ -150,6 +150,7 @@ struct w1_bus_master
 
 	/** Really nice hardware can handles the different types of ROM search
 	 *  w1_master* is passed to the slave found callback.
+	 *  u8 is search_type, W1_SEARCH or W1_ALARM_SEARCH
 	 */
 	void		(*search)(void *, struct w1_master *,
 		u8, w1_slave_found_callback);

@@ -177,6 +178,8 @@ struct w1_master
 	int			initialized;
 	u32			id;
 	int			search_count;
+	/* id to start searching on, to continue a search or 0 to restart */
+	u64			search_id;
 
 	atomic_t		refcnt;
 

index 4c89f85..97b35cb 100644
@@ -56,8 +56,6 @@ module_param_named(slave_ttl, w1_max_slave_ttl, int, 0);
 DEFINE_MUTEX(w1_mlock);
 LIST_HEAD(w1_masters);
 
-static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn);
-
 static int w1_master_match(struct device *dev, struct device_driver *drv)
 {
 	return 1;

@@ -444,7 +442,7 @@ static int w1_atoreg_num(struct device *dev, const char *buf, size_t count,
 /* Searches the slaves in the w1_master and returns a pointer or NULL.
  * Note: must hold the mutex
  */
-static struct w1_slave *w1_slave_search_device(struct w1_master *dev,
+struct w1_slave *w1_slave_search_device(struct w1_master *dev,
 	struct w1_reg_num *rn)
 {
 	struct w1_slave *sl;

@@ -711,7 +709,7 @@ static int __w1_attach_slave_device(struct w1_slave *sl)
 	return 0;
 }
 
-static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
+int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
 {
 	struct w1_slave *sl;
 	struct w1_family *f;

index 80fbdf9..3376bfb 100644
@@ -213,6 +213,8 @@ struct w1_slave *w1_search_slave(struct w1_reg_num *id);
 void w1_slave_found(struct w1_master *dev, u64 rn);
 void w1_search_process_cb(struct w1_master *dev, u8 search_type,
 	w1_slave_found_callback cb);
+struct w1_slave *w1_slave_search_device(struct w1_master *dev,
+	struct w1_reg_num *rn);
 struct w1_master *w1_search_master_id(u32 id);
 
 /* Disconnect and reconnect devices in the given family.  Used for finding

@@ -221,6 +223,7 @@ struct w1_master *w1_search_master_id(u32 id);
  * has just been registered, to 0 when it has been unregistered.
  */
 void w1_reconnect_slaves(struct w1_family *f, int attach);
+int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn);
 void w1_slave_detach(struct w1_slave *sl);
 
 u8 w1_triplet(struct w1_master *dev, int bdir);

173 lines not on this page · raw message

index b0922dc..ea9f3e4 100644
@@ -27,6 +27,17 @@
 
 #include "w1.h"
 
+/** enum w1_netlink_message_types - message type
+ *
+ * @W1_SLAVE_ADD: notification that a slave device was added
+ * @W1_SLAVE_REMOVE: notification that a slave device was removed
+ * @W1_MASTER_ADD: notification that a new bus master was added
+ * @W1_MASTER_REMOVE: notification that a bus masterwas removed
+ * @W1_MASTER_CMD: initiate operations on a specific master
+ * @W1_SLAVE_CMD: sends reset, selects the slave, then does a read/write/touch
+ * operation
+ * @W1_LIST_MASTERS: used to determine the bus master identifiers
+ */
 enum w1_netlink_message_types {
 	W1_SLAVE_ADD = 0,
 	W1_SLAVE_REMOVE,

@@ -52,6 +63,21 @@ struct w1_netlink_msg
 	__u8				data[0];
 };
 
+/** enum w1_commands - commands available for master or slave operations
+ * @W1_CMD_READ: read len bytes
+ * @W1_CMD_WRITE: write len bytes
+ * @W1_CMD_SEARCH: initiate a standard search, returns only the slave
+ * devices found during that search
+ * @W1_CMD_ALARM_SEARCH: search for devices that are currently alarming
+ * @W1_CMD_TOUCH: Touches a series of bytes.
+ * @W1_CMD_RESET: sends a bus reset on the given master
+ * @W1_CMD_SLAVE_ADD: adds a slave to the given master,
+ * 8 byte slave id at data[0]
+ * @W1_CMD_SLAVE_REMOVE: removes a slave to the given master,
+ * 8 byte slave id at data[0]
+ * @W1_CMD_LIST_SLAVES: list of slaves registered on this master
+ * @W1_CMD_MAX: number of available commands
+ */
 enum w1_commands {
 	W1_CMD_READ = 0,
 	W1_CMD_WRITE,

@@ -59,7 +85,10 @@ enum w1_commands {
 	W1_CMD_ALARM_SEARCH,
 	W1_CMD_TOUCH,
 	W1_CMD_RESET,
-	W1_CMD_MAX,
+	W1_CMD_SLAVE_ADD,
+	W1_CMD_SLAVE_REMOVE,
+	W1_CMD_LIST_SLAVES,
+	W1_CMD_MAX
 };
 
 struct w1_netlink_cmd

index 97b35cb..53846c7 100644
@@ -79,19 +79,10 @@ static void w1_slave_release(struct device *dev)
 {
 	struct w1_slave *sl = dev_to_w1_slave(dev);
 
-	dev_dbg(dev, "%s: Releasing %s.\n", __func__, sl->name);
-
-	while (atomic_read(&sl->refcnt)) {
-		dev_dbg(dev, "Waiting for %s to become free: refcnt=%d.\n",
-				sl->name, atomic_read(&sl->refcnt));
-		if (msleep_interruptible(1000))
-			flush_signals(current);
-	}
+	dev_dbg(dev, "%s: Releasing %s [%p]\n", __func__, sl->name, sl);
 
 	w1_family_put(sl->family);
 	sl->master->slave_count--;
-
-	complete(&sl->released);
 }
 
 static ssize_t name_show(struct device *dev, struct device_attribute *attr, char *buf)

@@ -277,7 +268,6 @@ static ssize_t w1_master_attribute_store_pullup(struct device *dev,
 	mutex_lock(&md->mutex);
 	md->enable_pullup = tmp;
 	mutex_unlock(&md->mutex);
-	wake_up_process(md->thread);
 
 	return count;
 }

@@ -370,23 +360,20 @@ static ssize_t w1_master_attribute_show_slaves(struct device *dev,
 {
 	struct w1_master *md = dev_to_w1_master(dev);
 	int c = PAGE_SIZE;
+	struct list_head *ent, *n;
+	struct w1_slave *sl = NULL;
 
-	mutex_lock(&md->mutex);
-
-	if (md->slave_count == 0)
-		c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n");
-	else {
-		struct list_head *ent, *n;
-		struct w1_slave *sl;
+	mutex_lock(&md->list_mutex);
 
-		list_for_each_safe(ent, n, &md->slist) {
-			sl = list_entry(ent, struct w1_slave, w1_slave_entry);
+	list_for_each_safe(ent, n, &md->slist) {
+		sl = list_entry(ent, struct w1_slave, w1_slave_entry);
 
-			c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name);
-		}
+		c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name);
 	}
+	if (!sl)
+		c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n");
 
-	mutex_unlock(&md->mutex);
+	mutex_unlock(&md->list_mutex);
 
 	return PAGE_SIZE - c;
 }

@@ -440,19 +427,22 @@ static int w1_atoreg_num(struct device *dev, const char *buf, size_t count,
 }
 
 /* Searches the slaves in the w1_master and returns a pointer or NULL.
- * Note: must hold the mutex
+ * Note: must not hold list_mutex
  */
 struct w1_slave *w1_slave_search_device(struct w1_master *dev,
 	struct w1_reg_num *rn)
 {
 	struct w1_slave *sl;
+	mutex_lock(&dev->list_mutex);
 	list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
 		if (sl->reg_num.family == rn->family &&
 				sl->reg_num.id == rn->id &&
 				sl->reg_num.crc == rn->crc) {
+			mutex_unlock(&dev->list_mutex);
 			return sl;
 		}
 	}
+	mutex_unlock(&dev->list_mutex);
 	return NULL;
 }
 

@@ -509,7 +499,10 @@ static ssize_t w1_master_attribute_store_remove(struct device *dev,
 	mutex_lock(&md->mutex);
 	sl = w1_slave_search_device(md, &rn);
 	if (sl) {
-		w1_slave_detach(sl);
+		result = w1_slave_detach(sl);
+		/* refcnt 0 means it was detached in the call */
+		if (result == 0)
+			result = count;
 	} else {
 		dev_info(dev, "Device %02x-%012llx doesn't exists\n", rn.family,
 			(unsigned long long)rn.id);

@@ -704,7 +697,9 @@ static int __w1_attach_slave_device(struct w1_slave *sl)
 	dev_set_uevent_suppress(&sl->dev, false);
 	kobject_uevent(&sl->dev.kobj, KOBJ_ADD);
 
+	mutex_lock(&sl->master->list_mutex);
 	list_add_tail(&sl->w1_slave_entry, &sl->master->slist);
+	mutex_unlock(&sl->master->list_mutex);
 
 	return 0;
 }

@@ -731,8 +726,8 @@ int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
 
 	memset(&msg, 0, sizeof(msg));
 	memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
-	atomic_set(&sl->refcnt, 0);
-	init_completion(&sl->released);
+	atomic_set(&sl->refcnt, 1);
+	atomic_inc(&sl->master->refcnt);
 
 	/* slave modules need to be loaded in a context with unlocked mutex */
 	mutex_unlock(&dev->mutex);

@@ -772,23 +767,48 @@ int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
 	return 0;
 }
 
-void w1_slave_detach(struct w1_slave *sl)
+int w1_unref_slave(struct w1_slave *sl)
 {
-	struct w1_netlink_msg msg;
-
-	dev_dbg(&sl->dev, "%s: detaching %s [%p].\n", __func__, sl->name, sl);
-
-	list_del(&sl->w1_slave_entry);
-
-	memset(&msg, 0, sizeof(msg));
-	memcpy(msg.id.id, &sl->reg_num, sizeof(msg.id));
-	msg.type = W1_SLAVE_REMOVE;
-	w1_netlink_send(sl->master, &msg);
-
-	device_unregister(&sl->dev);
+	struct w1_master *dev = sl->master;
+	int refcnt;
+	mutex_lock(&dev->list_mutex);
+	refcnt = atomic_sub_return(1, &sl->refcnt);
+	if (refcnt == 0) {
+		struct w1_netlink_msg msg;
+
+		dev_dbg(&sl->dev, "%s: detaching %s [%p].\n", __func__,
+			sl->name, sl);
+
+		list_del(&sl->w1_slave_entry);
+
+		memset(&msg, 0, sizeof(msg));
+		memcpy(msg.id.id, &sl->reg_num, sizeof(msg.id));
+		msg.type = W1_SLAVE_REMOVE;
+		w1_netlink_send(sl->master, &msg);
+
+		device_unregister(&sl->dev);
+		#ifdef DEBUG
+		memset(sl, 0, sizeof(*sl));
+		#endif
+		kfree(sl);
+	}
+	atomic_dec(&dev->refcnt);
+	mutex_unlock(&dev->list_mutex);
+	return refcnt;
+}
 
-	wait_for_completion(&sl->released);
-	kfree(sl);
+int w1_slave_detach(struct w1_slave *sl)
+{
+	/* Only detach a slave once as it decreases the refcnt each time. */
+	int destroy_now;
+	mutex_lock(&sl->master->list_mutex);
+	destroy_now = !test_bit(W1_SLAVE_DETACH, &sl->flags);
+	set_bit(W1_SLAVE_DETACH, &sl->flags);
+	mutex_unlock(&sl->master->list_mutex);
+
+	if (destroy_now)
+		destroy_now = !w1_unref_slave(sl);
+	return destroy_now ? 0 : -EBUSY;
 }
 
 struct w1_master *w1_search_master_id(u32 id)

@@ -817,7 +837,7 @@ struct w1_slave *w1_search_slave(struct w1_reg_num *id)
 
 	mutex_lock(&w1_mlock);
 	list_for_each_entry(dev, &w1_masters, w1_master_entry) {
-		mutex_lock(&dev->mutex);
+		mutex_lock(&dev->list_mutex);
 		list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
 			if (sl->reg_num.family == id->family &&
 					sl->reg_num.id == id->id &&

@@ -828,7 +848,7 @@ struct w1_slave *w1_search_slave(struct w1_reg_num *id)
 				break;
 			}
 		}
-		mutex_unlock(&dev->mutex);
+		mutex_unlock(&dev->list_mutex);
 
 		if (found)
 			break;

@@ -848,6 +868,7 @@ void w1_reconnect_slaves(struct w1_family *f, int attach)
 		dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
 			"for family %02x.\n", dev->name, f->fid);
 		mutex_lock(&dev->mutex);
+		mutex_lock(&dev->list_mutex);
 		list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
 			/* If it is a new family, slaves with the default
 			 * family driver and are that family will be

@@ -859,14 +880,19 @@ void w1_reconnect_slaves(struct w1_family *f, int attach)
 				(!attach && sl->family->fid == f->fid)) {
 				struct w1_reg_num rn;
 
+				mutex_unlock(&dev->list_mutex);
 				memcpy(&rn, &sl->reg_num, sizeof(rn));
-				w1_slave_detach(sl);
-
-				w1_attach_slave_device(dev, &rn);
+				/* If it was already in use let the automatic
+				 * scan pick it up again later.
+				 */
+				if (!w1_slave_detach(sl))
+					w1_attach_slave_device(dev, &rn);
+				mutex_lock(&dev->list_mutex);
 			}
 		}
 		dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
 			"has been finished.\n", dev->name);
+		mutex_unlock(&dev->list_mutex);
 		mutex_unlock(&dev->mutex);
 	}
 	mutex_unlock(&w1_mlock);

@@ -1020,17 +1046,24 @@ void w1_search_process_cb(struct w1_master *dev, u8 search_type,
 {
 	struct w1_slave *sl, *sln;
 
+	mutex_lock(&dev->list_mutex);
 	list_for_each_entry(sl, &dev->slist, w1_slave_entry)
 		clear_bit(W1_SLAVE_ACTIVE, &sl->flags);
+	mutex_unlock(&dev->list_mutex);
 
 	w1_search_devices(dev, search_type, cb);
 
+	mutex_lock(&dev->list_mutex);
 	list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
-		if (!test_bit(W1_SLAVE_ACTIVE, &sl->flags) && !--sl->ttl)
+		if (!test_bit(W1_SLAVE_ACTIVE, &sl->flags) && !--sl->ttl) {
+			mutex_unlock(&dev->list_mutex);
 			w1_slave_detach(sl);
+			mutex_lock(&dev->list_mutex);
+		}
 		else if (test_bit(W1_SLAVE_ACTIVE, &sl->flags))
 			sl->ttl = dev->slave_ttl;
 	}
+	mutex_unlock(&dev->list_mutex);
 
 	if (dev->search_count > 0)
 		dev->search_count--;

@@ -1041,6 +1074,26 @@ static void w1_search_process(struct w1_master *dev, u8 search_type)
 	w1_search_process_cb(dev, search_type, w1_slave_found);
 }
 
+int w1_process_callbacks(struct w1_master *dev)
+{
+	int ret = 0;
+	struct w1_async_cmd *async_cmd, *async_n;
+
+	/* The list can be added to in another thread, loop until it is empty */
+	while (!list_empty(&dev->async_list)) {
+		list_for_each_entry_safe(async_cmd, async_n, &dev->async_list,
+			async_entry) {
+			/* drop the lock, if it is a search it can take a long
+			 * time */
+			mutex_unlock(&dev->list_mutex);
+			async_cmd->cb(dev, async_cmd);
+			ret = 1;
+			mutex_lock(&dev->list_mutex);
+		}
+	}
+	return ret;
+}
+
 int w1_process(void *data)
 {
 	struct w1_master *dev = (struct w1_master *) data;

@@ -1048,23 +1101,46 @@ int w1_process(void *data)
 	 * time can be calculated in jiffies once.
 	 */
 	const unsigned long jtime = msecs_to_jiffies(w1_timeout * 1000);
+	/* remainder if it woke up early */
+	unsigned long jremain = 0;
 
-	while (!kthread_should_stop()) {
-		if (dev->search_count) {
+	for (;;) {
+
+		if (!jremain && dev->search_count) {
 			mutex_lock(&dev->mutex);
 			w1_search_process(dev, W1_SEARCH);
 			mutex_unlock(&dev->mutex);
 		}
 
+		mutex_lock(&dev->list_mutex);
+		/* Note, w1_process_callback drops the lock while processing,
+		 * but locks it again before returning.
+		 */
+		if (!w1_process_callbacks(dev) && jremain) {
+			/* a wake up is either to stop the thread, process
+			 * callbacks, or search, it isn't process callbacks, so
+			 * schedule a search.
+			 */
+			jremain = 1;
+		}
+
 		try_to_freeze();
 		__set_current_state(TASK_INTERRUPTIBLE);
 
+		/* hold list_mutex until after interruptible to prevent loosing
+		 * the wakeup signal when async_cmd is added.
+		 */
+		mutex_unlock(&dev->list_mutex);
+
 		if (kthread_should_stop())
 			break;
 
 		/* Only sleep when the search is active. */
-		if (dev->search_count)
-			schedule_timeout(jtime);
+		if (dev->search_count) {
+			if (!jremain)
+				jremain = jtime;
+			jremain = schedule_timeout(jremain);
+		}
 		else
 			schedule();
 	}

index 3376bfb..a096ef4 100644
@@ -58,6 +58,7 @@ struct w1_reg_num
 #define W1_RESUME_CMD		0xA5
 
 #define W1_SLAVE_ACTIVE		0
+#define W1_SLAVE_DETACH		1
 
 struct w1_slave
 {

@@ -74,7 +75,6 @@ struct w1_slave
 	struct w1_family	*family;
 	void			*family_data;
 	struct device		dev;
-	struct completion	released;
 };
 
 typedef void (*w1_slave_found_callback)(struct w1_master *, u64);

@@ -171,7 +171,14 @@ struct w1_master
 	struct list_head	w1_master_entry;
 	struct module		*owner;
 	unsigned char		name[W1_MAXNAMELEN];
+	/* list_mutex protects just slist and async_list so slaves can be
+	 * searched for and async commands added while the master has
+	 * w1_master.mutex locked and is operating on the bus.
+	 * lock order w1_mlock, w1_master.mutex, w1_master_list_mutex
+	 */
+	struct mutex		list_mutex;
 	struct list_head	slist;
+	struct list_head	async_list;
 	int			max_slave_count, slave_count;
 	unsigned long		attempts;
 	int			slave_ttl;

@@ -205,11 +212,29 @@ struct w1_master
 	u32			seq;
 };
 
+/**
+ * struct w1_async_cmd - execute callback from the w1_process kthread
+ * @async_entry: link entry
+ * @cb: callback function, must list_del and destroy this list before
+ * returning
+ *
+ * When inserted into the w1_master async_list, w1_process will execute
+ * the callback.  Embed this into the structure with the command details.
+ */
+struct w1_async_cmd {
+	struct list_head	async_entry;
+	void (*cb)(struct w1_master *dev, struct w1_async_cmd *async_cmd);
+};
+
 int w1_create_master_attributes(struct w1_master *);
 void w1_destroy_master_attributes(struct w1_master *master);
 void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb);
 void w1_search_devices(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb);
+/* call w1_unref_slave to release the reference counts w1_search_slave added */
 struct w1_slave *w1_search_slave(struct w1_reg_num *id);
+/* decrements the reference on sl->master and sl, and cleans up if zero
+ * returns the reference count after it has been decremented */
+int w1_unref_slave(struct w1_slave *sl);
 void w1_slave_found(struct w1_master *dev, u64 rn);
 void w1_search_process_cb(struct w1_master *dev, u8 search_type,
 	w1_slave_found_callback cb);

@@ -224,7 +249,8 @@ struct w1_master *w1_search_master_id(u32 id);
  */
 void w1_reconnect_slaves(struct w1_family *f, int attach);
 int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn);
-void w1_slave_detach(struct w1_slave *sl);
+/* 0 success, otherwise EBUSY */
+int w1_slave_detach(struct w1_slave *sl);
 
 u8 w1_triplet(struct w1_master *dev, int bdir);
 void w1_write_8(struct w1_master *, u8);

@@ -260,6 +286,8 @@ extern int w1_max_slave_ttl;
 extern struct list_head w1_masters;
 extern struct mutex w1_mlock;
 
+/* returns 1 if there were commands to executed 0 otherwise */
+extern int w1_process_callbacks(struct w1_master *dev);
 extern int w1_process(void *);
 
 #endif /* __KERNEL__ */

index 423f3c2..66b2caa 100644
@@ -75,8 +75,10 @@ static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl,
 	atomic_set(&dev->refcnt, 2);
 
 	INIT_LIST_HEAD(&dev->slist);
+	INIT_LIST_HEAD(&dev->async_list);
 	mutex_init(&dev->mutex);
 	mutex_init(&dev->bus_mutex);
+	mutex_init(&dev->list_mutex);
 
 	memcpy(&dev->dev, device, sizeof(struct device));
 	dev_set_name(&dev->dev, "w1_bus_master%u", dev->id);

@@ -188,17 +190,22 @@ void __w1_remove_master_device(struct w1_master *dev)
 	struct w1_netlink_msg msg;
 	struct w1_slave *sl, *sln;
 
-	set_bit(W1_ABORT_SEARCH, &dev->flags);
-	kthread_stop(dev->thread);
-
 	mutex_lock(&w1_mlock);
 	list_del(&dev->w1_master_entry);
 	mutex_unlock(&w1_mlock);
 
+	set_bit(W1_ABORT_SEARCH, &dev->flags);
+	kthread_stop(dev->thread);
+
 	mutex_lock(&dev->mutex);
-	list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry)
+	mutex_lock(&dev->list_mutex);
+	list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
+		mutex_unlock(&dev->list_mutex);
 		w1_slave_detach(sl);
+		mutex_lock(&dev->list_mutex);
+	}
 	w1_destroy_master_attributes(dev);
+	mutex_unlock(&dev->list_mutex);
 	mutex_unlock(&dev->mutex);
 	atomic_dec(&dev->refcnt);
 

@@ -208,7 +215,9 @@ void __w1_remove_master_device(struct w1_master *dev)
 
 		if (msleep_interruptible(1000))
 			flush_signals(current);
+		w1_process_callbacks(dev);
 	}
+	w1_process_callbacks(dev);
 
 	memset(&msg, 0, sizeof(msg));
 	msg.id.mst.id = dev->id;

215 lines not on this page · raw message

index adcca03..d12cc94 100644
@@ -145,7 +145,7 @@ static void cn_test_timer_func(unsigned long __data)
 
 		memcpy(m + 1, data, m->len);
 
-		cn_netlink_send(m, 0, GFP_ATOMIC);
+		cn_netlink_send(m, 0, 0, GFP_ATOMIC);
 		kfree(m);
 	}
 

index 18c5b9b..148d707 100644
@@ -95,7 +95,7 @@ void proc_fork_connector(struct task_struct *task)
 	msg->len = sizeof(*ev);
 	msg->flags = 0; /* not used */
 	/*  If cn_netlink_send() failed, the data is not sent */
-	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
+	cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
 }
 
 void proc_exec_connector(struct task_struct *task)

@@ -122,7 +122,7 @@ void proc_exec_connector(struct task_struct *task)
 	msg->ack = 0; /* not used */
 	msg->len = sizeof(*ev);
 	msg->flags = 0; /* not used */
-	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
+	cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
 }
 
 void proc_id_connector(struct task_struct *task, int which_id)

@@ -163,7 +163,7 @@ void proc_id_connector(struct task_struct *task, int which_id)
 	msg->ack = 0; /* not used */
 	msg->len = sizeof(*ev);
 	msg->flags = 0; /* not used */
-	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
+	cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
 }
 
 void proc_sid_connector(struct task_struct *task)

@@ -190,7 +190,7 @@ void proc_sid_connector(struct task_struct *task)
 	msg->ack = 0; /* not used */
 	msg->len = sizeof(*ev);
 	msg->flags = 0; /* not used */
-	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
+	cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
 }
 
 void proc_ptrace_connector(struct task_struct *task, int ptrace_id)

@@ -225,7 +225,7 @@ void proc_ptrace_connector(struct task_struct *task, int ptrace_id)
 	msg->ack = 0; /* not used */
 	msg->len = sizeof(*ev);
 	msg->flags = 0; /* not used */
-	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
+	cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
 }
 
 void proc_comm_connector(struct task_struct *task)

@@ -253,7 +253,7 @@ void proc_comm_connector(struct task_struct *task)
 	msg->ack = 0; /* not used */
 	msg->len = sizeof(*ev);
 	msg->flags = 0; /* not used */
-	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
+	cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
 }
 
 void proc_coredump_connector(struct task_struct *task)

@@ -280,7 +280,7 @@ void proc_coredump_connector(struct task_struct *task)
 	msg->ack = 0; /* not used */
 	msg->len = sizeof(*ev);
 	msg->flags = 0; /* not used */
-	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
+	cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
 }
 
 void proc_exit_connector(struct task_struct *task)

@@ -309,7 +309,7 @@ void proc_exit_connector(struct task_struct *task)
 	msg->ack = 0; /* not used */
 	msg->len = sizeof(*ev);
 	msg->flags = 0; /* not used */
-	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
+	cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
 }
 
 /*

@@ -343,7 +343,7 @@ static void cn_proc_ack(int err, int rcvd_seq, int rcvd_ack)
 	msg->ack = rcvd_ack + 1;
 	msg->len = sizeof(*ev);
 	msg->flags = 0; /* not used */
-	cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
+	cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
 }
 
 /**

index a36749f..77afe74 100644
@@ -50,7 +50,7 @@ static int cn_already_initialized;
  *
  * Sequence number is incremented with each message to be sent.
  *
- * If we expect reply to our message then the sequence number in
+ * If we expect a reply to our message then the sequence number in
  * received message MUST be the same as in original message, and
  * acknowledge number MUST be the same + 1.
  *

@@ -62,8 +62,11 @@ static int cn_already_initialized;
  * the acknowledgement number in the original message + 1, then it is
  * a new message.
  *
+ * The message is sent to, the portid if given, the group if given, both if
+ * both, or if both are zero then the group is looked up and sent there.
  */
-int cn_netlink_send(struct cn_msg *msg, u32 __group, gfp_t gfp_mask)
+int cn_netlink_send(struct cn_msg *msg, u32 portid, u32 __group,
+	gfp_t gfp_mask)
 {
 	struct cn_callback_entry *__cbq;
 	unsigned int size;

@@ -74,7 +77,9 @@ int cn_netlink_send(struct cn_msg *msg, u32 __group, gfp_t gfp_mask)
 	u32 group = 0;
 	int found = 0;
 
-	if (!__group) {
+	if (portid || __group) {
+		group = __group;
+	} else {
 		spin_lock_bh(&dev->cbdev->queue_lock);
 		list_for_each_entry(__cbq, &dev->cbdev->queue_list,
 				    callback_entry) {

@@ -88,11 +93,9 @@ int cn_netlink_send(struct cn_msg *msg, u32 __group, gfp_t gfp_mask)
 
 		if (!found)
 			return -ENODEV;
-	} else {
-		group = __group;
 	}
 
-	if (!netlink_has_listeners(dev->nls, group))
+	if (!portid && !netlink_has_listeners(dev->nls, group))
 		return -ESRCH;
 
 	size = sizeof(*msg) + msg->len;

@@ -113,7 +116,10 @@ int cn_netlink_send(struct cn_msg *msg, u32 __group, gfp_t gfp_mask)
 
 	NETLINK_CB(skb).dst_group = group;
 
-	return netlink_broadcast(dev->nls, skb, 0, group, gfp_mask);
+	if (group)
+		return netlink_broadcast(dev->nls, skb, portid, group,
+					 gfp_mask);
+	return netlink_unicast(dev->nls, skb, portid, !(gfp_mask&__GFP_WAIT));
 }
 EXPORT_SYMBOL_GPL(cn_netlink_send);
 

index 09988b2..ea85253 100644
@@ -113,7 +113,7 @@ kvp_register(int reg_value)
 		kvp_msg->kvp_hdr.operation = reg_value;
 		strcpy(version, HV_DRV_VERSION);
 		msg->len = sizeof(struct hv_kvp_msg);
-		cn_netlink_send(msg, 0, GFP_ATOMIC);
+		cn_netlink_send(msg, 0, 0, GFP_ATOMIC);
 		kfree(msg);
 	}
 }

@@ -435,7 +435,7 @@ kvp_send_key(struct work_struct *dummy)
 	}
 
 	msg->len = sizeof(struct hv_kvp_msg);
-	cn_netlink_send(msg, 0, GFP_ATOMIC);
+	cn_netlink_send(msg, 0, 0, GFP_ATOMIC);
 	kfree(msg);
 
 	return;

index 0c35462..34f14fd 100644
@@ -98,7 +98,7 @@ static void vss_send_op(struct work_struct *dummy)
 	vss_msg->vss_hdr.operation = op;
 	msg->len = sizeof(struct hv_vss_msg);
 
-	cn_netlink_send(msg, 0, GFP_ATOMIC);
+	cn_netlink_send(msg, 0, 0, GFP_ATOMIC);
 	kfree(msg);
 
 	return;

index 08d9a20..b428c0a 100644
@@ -66,7 +66,7 @@ static int dm_ulog_sendto_server(struct dm_ulog_request *tfr)
 	msg->seq = tfr->seq;
 	msg->len = sizeof(struct dm_ulog_request) + tfr->data_size;
 
-	r = cn_netlink_send(msg, 0, gfp_any());
+	r = cn_netlink_send(msg, 0, 0, gfp_any());
 
 	return r;
 }

index 256fba7..1f38445 100644
@@ -190,7 +190,7 @@ static int uvesafb_exec(struct uvesafb_ktask *task)
 	uvfb_tasks[seq] = task;
 	mutex_unlock(&uvfb_lock);
 
-	err = cn_netlink_send(m, 0, GFP_KERNEL);
+	err = cn_netlink_send(m, 0, 0, GFP_KERNEL);
 	if (err == -ESRCH) {
 		/*
 		 * Try to start the userspace helper if sending

@@ -204,7 +204,7 @@ static int uvesafb_exec(struct uvesafb_ktask *task)
 					"helper is installed and executable\n");
 		} else {
 			v86d_started = 1;
-			err = cn_netlink_send(m, 0, gfp_any());
+			err = cn_netlink_send(m, 0, 0, gfp_any());
 			if (err == -ENOBUFS)
 				err = 0;
 		}

index 06d614a..b63109a 100644
@@ -45,7 +45,7 @@ void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg)
 
 	memcpy(w, msg, sizeof(struct w1_netlink_msg));
 
-	cn_netlink_send(m, 0, GFP_KERNEL);
+	cn_netlink_send(m, 0, 0, GFP_KERNEL);
 }
 
 static void w1_send_slave(struct w1_master *dev, u64 rn)

@@ -60,7 +60,7 @@ static void w1_send_slave(struct w1_master *dev, u64 rn)
 
 	if (avail < 8) {
 		msg->ack++;
-		cn_netlink_send(msg, 0, GFP_KERNEL);
+		cn_netlink_send(msg, 0, 0, GFP_KERNEL);
 
 		msg->len = sizeof(struct w1_netlink_msg) +
 			sizeof(struct w1_netlink_cmd);

@@ -131,7 +131,7 @@ static int w1_get_slaves(struct w1_master *dev,
 	}
 
 	msg->ack = 0;
-	cn_netlink_send(msg, 0, GFP_KERNEL);
+	cn_netlink_send(msg, 0, 0, GFP_KERNEL);
 
 	dev->priv = NULL;
 	dev->priv_size = 0;

@@ -173,7 +173,7 @@ static int w1_send_read_reply(struct cn_msg *msg, struct w1_netlink_msg *hdr,
 
 	memcpy(c->data, cmd->data, c->len);
 
-	err = cn_netlink_send(cm, 0, GFP_KERNEL);
+	err = cn_netlink_send(cm, 0, 0, GFP_KERNEL);
 
 	kfree(data);
 

@@ -316,7 +316,7 @@ static int w1_process_command_root(struct cn_msg *msg, struct w1_netlink_msg *mc
 	mutex_lock(&w1_mlock);
 	list_for_each_entry(m, &w1_masters, w1_master_entry) {
 		if (cn->len + sizeof(*id) > PAGE_SIZE - sizeof(struct cn_msg)) {
-			cn_netlink_send(cn, 0, GFP_KERNEL);
+			cn_netlink_send(cn, 0, 0, GFP_KERNEL);
 			cn->ack++;
 			cn->len = sizeof(struct w1_netlink_msg);
 			w->len = 0;

@@ -329,7 +329,7 @@ static int w1_process_command_root(struct cn_msg *msg, struct w1_netlink_msg *mc
 		id++;
 	}
 	cn->ack = 0;
-	cn_netlink_send(cn, 0, GFP_KERNEL);
+	cn_netlink_send(cn, 0, 0, GFP_KERNEL);
 	mutex_unlock(&w1_mlock);
 
 	kfree(cn);

@@ -364,7 +364,7 @@ static int w1_netlink_send_error(struct cn_msg *rcmsg, struct w1_netlink_msg *rm
 		cmsg->len += sizeof(*cmd);
 	}
 
-	error = cn_netlink_send(cmsg, 0, GFP_KERNEL);
+	error = cn_netlink_send(cmsg, 0, 0, GFP_KERNEL);
 	kfree(cmsg);
 
 	return error;

index b2b5a41..be9c4747 100644
@@ -71,7 +71,7 @@ struct cn_dev {
 int cn_add_callback(struct cb_id *id, const char *name,
 		    void (*callback)(struct cn_msg *, struct netlink_skb_parms *));
 void cn_del_callback(struct cb_id *);
-int cn_netlink_send(struct cn_msg *, u32, gfp_t);
+int cn_netlink_send(struct cn_msg *msg, u32 portid, u32 group, gfp_t gfp_mask);
 
 int cn_queue_add_callback(struct cn_queue_dev *dev, const char *name,
 			  struct cb_id *id,

index a096ef4..390a730 100644
@@ -210,6 +210,11 @@ struct w1_master
 	struct w1_bus_master	*bus_master;
 
 	u32			seq;
+	/* port id to send netlink responses to.  The value is temporarily
+	 * stored here while processing a message, set after locking the
+	 * mutex, zero before unlocking the mutex.
+	 */
+	u32			portid;
 };
 
 /**

161 lines not on this page · raw message

index 4f7e1d7..6a3d0a1 100644
@@ -1,5 +1,5 @@
 /*
- *	dscore.c
+ *	ds2490.c  USB to one wire bridge
  *
  * Copyright (c) 2004 Evgeniy Polyakov <[email protected]>
  *

@@ -28,6 +28,10 @@
 #include "../w1_int.h"
 #include "../w1.h"
 
+/* USB Standard */
+/* USB Control request vendor type */
+#define VENDOR				0x40
+
 /* COMMAND TYPE CODES */
 #define CONTROL_CMD			0x00
 #define COMM_CMD			0x01

@@ -107,6 +111,8 @@
 #define ST_HALT				0x10  /* DS2490 is currently halted */
 #define ST_IDLE				0x20  /* DS2490 is currently idle */
 #define ST_EPOF				0x80
+/* Status transfer size, 16 bytes status, 16 byte result flags */
+#define ST_SIZE				0x20
 
 /* Result Register flags */
 #define RR_DETECT			0xA5 /* New device detected */

@@ -198,7 +204,7 @@ static int ds_send_control_cmd(struct ds_device *dev, u16 value, u16 index)
 	int err;
 
 	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
-			CONTROL_CMD, 0x40, value, index, NULL, 0, 1000);
+			CONTROL_CMD, VENDOR, value, index, NULL, 0, 1000);
 	if (err < 0) {
 		printk(KERN_ERR "Failed to send command control message %x.%x: err=%d.\n",
 				value, index, err);

@@ -213,7 +219,7 @@ static int ds_send_control_mode(struct ds_device *dev, u16 value, u16 index)
 	int err;
 
 	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
-			MODE_CMD, 0x40, value, index, NULL, 0, 1000);
+			MODE_CMD, VENDOR, value, index, NULL, 0, 1000);
 	if (err < 0) {
 		printk(KERN_ERR "Failed to send mode control message %x.%x: err=%d.\n",
 				value, index, err);

@@ -228,7 +234,7 @@ static int ds_send_control(struct ds_device *dev, u16 value, u16 index)
 	int err;
 
 	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, dev->ep[EP_CONTROL]),
-			COMM_CMD, 0x40, value, index, NULL, 0, 1000);
+			COMM_CMD, VENDOR, value, index, NULL, 0, 1000);
 	if (err < 0) {
 		printk(KERN_ERR "Failed to send control message %x.%x: err=%d.\n",
 				value, index, err);

@@ -353,7 +359,7 @@ static int ds_recv_data(struct ds_device *dev, unsigned char *buf, int size)
 	err = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_DATA_IN]),
 				buf, size, &count, 1000);
 	if (err < 0) {
-		u8 buf[0x20];
+		u8 buf[ST_SIZE];
 		int count;
 
 		printk(KERN_INFO "Clearing ep0x%x.\n", dev->ep[EP_DATA_IN]);

@@ -398,7 +404,7 @@ int ds_stop_pulse(struct ds_device *dev, int limit)
 {
 	struct ds_status st;
 	int count = 0, err = 0;
-	u8 buf[0x20];
+	u8 buf[ST_SIZE];
 
 	do {
 		err = ds_send_control(dev, CTL_HALT_EXE_IDLE, 0);

@@ -450,10 +456,11 @@ int ds_detect(struct ds_device *dev, struct ds_status *st)
 
 static int ds_wait_status(struct ds_device *dev, struct ds_status *st)
 {
-	u8 buf[0x20];
+	u8 buf[ST_SIZE];
 	int err, count = 0;
 
 	do {
+		st->status = 0;
 		err = ds_recv_status_nodump(dev, st, buf, sizeof(buf));
 #if 0
 		if (err >= 0) {

@@ -464,7 +471,7 @@ static int ds_wait_status(struct ds_device *dev, struct ds_status *st)
 			printk("\n");
 		}
 #endif
-	} while (!(buf[0x08] & ST_IDLE) && !(err < 0) && ++count < 100);
+	} while (!(st->status & ST_IDLE) && !(err < 0) && ++count < 100);
 
 	if (err >= 16 && st->status & ST_EPOF) {
 		printk(KERN_INFO "Resetting device after ST_EPOF.\n");

index 6a3d0a1..cd59e12 100644
@@ -252,7 +252,8 @@ static int ds_recv_status_nodump(struct ds_device *dev, struct ds_status *st,
 	memset(st, 0, sizeof(*st));
 
 	count = 0;
-	err = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_STATUS]), buf, size, &count, 100);
+	err = usb_interrupt_msg(dev->udev, usb_rcvintpipe(dev->udev,
+		dev->ep[EP_STATUS]), buf, size, &count, 100);
 	if (err < 0) {
 		printk(KERN_ERR "Failed to read 1-wire data from 0x%x: err=%d.\n", dev->ep[EP_STATUS], err);
 		return err;

@@ -917,7 +918,7 @@ static int ds_probe(struct usb_interface *intf,
 	struct usb_endpoint_descriptor *endpoint;
 	struct usb_host_interface *iface_desc;
 	struct ds_device *dev;
-	int i, err;
+	int i, err, alt;
 
 	dev = kmalloc(sizeof(struct ds_device), GFP_KERNEL);
 	if (!dev) {

@@ -935,20 +936,25 @@ static int ds_probe(struct usb_interface *intf,
 
 	usb_set_intfdata(intf, dev);
 
-	err = usb_set_interface(dev->udev, intf->altsetting[0].desc.bInterfaceNumber, 3);
+	err = usb_reset_configuration(dev->udev);
 	if (err) {
-		printk(KERN_ERR "Failed to set alternative setting 3 for %d interface: err=%d.\n",
-				intf->altsetting[0].desc.bInterfaceNumber, err);
+		dev_err(&dev->udev->dev,
+			"Failed to reset configuration: err=%d.\n", err);
 		goto err_out_clear;
 	}
 
-	err = usb_reset_configuration(dev->udev);
+	/* alternative 3, 1ms interrupt (greatly speeds search), 64 byte bulk */
+	alt = 3;
+	err = usb_set_interface(dev->udev,
+		intf->altsetting[alt].desc.bInterfaceNumber, alt);
 	if (err) {
-		printk(KERN_ERR "Failed to reset configuration: err=%d.\n", err);
+		dev_err(&dev->udev->dev, "Failed to set alternative setting %d "
+			"for %d interface: err=%d.\n", alt,
+			intf->altsetting[alt].desc.bInterfaceNumber, err);
 		goto err_out_clear;
 	}
 
-	iface_desc = &intf->altsetting[0];
+	iface_desc = &intf->altsetting[alt];
 	if (iface_desc->desc.bNumEndpoints != NUM_EP-1) {
 		printk(KERN_INFO "Num endpoints=%d. It is not DS9490R.\n", iface_desc->desc.bNumEndpoints);
 		err = -EINVAL;

142 lines not on this page · raw message

index 8b5ff33..1f11a20 100644
@@ -27,6 +27,7 @@
 #include <linux/sched.h>
 #include <linux/device.h>
 #include <linux/types.h>
+#include <linux/slab.h>
 #include <linux/delay.h>
 
 #include "../w1.h"

@@ -58,6 +59,19 @@ MODULE_ALIAS("w1-family-" __stringify(W1_THERM_DS28EA00));
 static int w1_strong_pullup = 1;
 module_param_named(strong_pullup, w1_strong_pullup, int, 0);
 
+static int w1_therm_add_slave(struct w1_slave *sl)
+{
+	sl->family_data = kzalloc(9, GFP_KERNEL);
+	if (!sl->family_data)
+		return -ENOMEM;
+	return 0;
+}
+
+static void w1_therm_remove_slave(struct w1_slave *sl)
+{
+	kfree(sl->family_data);
+	sl->family_data = NULL;
+}
 
 static ssize_t w1_slave_show(struct device *device,
 	struct device_attribute *attr, char *buf);

@@ -71,6 +85,8 @@ static struct attribute *w1_therm_attrs[] = {
 ATTRIBUTE_GROUPS(w1_therm);
 
 static struct w1_family_ops w1_therm_fops = {
+	.add_slave	= w1_therm_add_slave,
+	.remove_slave	= w1_therm_remove_slave,
 	.groups		= w1_therm_groups,
 };
 

@@ -253,12 +269,13 @@ static ssize_t w1_slave_show(struct device *device,
 	c -= snprintf(buf + PAGE_SIZE - c, c, ": crc=%02x %s\n",
 			   crc, (verdict) ? "YES" : "NO");
 	if (verdict)
-		memcpy(sl->rom, rom, sizeof(sl->rom));
+		memcpy(sl->family_data, rom, sizeof(rom));
 	else
 		dev_warn(device, "Read failed CRC check\n");
 
 	for (i = 0; i < 9; ++i)
-		c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ", sl->rom[i]);
+		c -= snprintf(buf + PAGE_SIZE - c, c, "%02x ",
+			      ((u8 *)sl->family_data)[i]);
 
 	c -= snprintf(buf + PAGE_SIZE - c, c, "t=%d\n",
 		w1_convert_temp(rom, sl->family->fid));

index 390a730..0eb5050 100644
@@ -67,7 +67,6 @@ struct w1_slave
 	struct list_head	w1_slave_entry;
 	struct w1_reg_num	reg_num;
 	atomic_t		refcnt;
-	u8			rom[9];
 	int			ttl;
 	unsigned long		flags;
 

index 53846c7..9eb816b 100644
@@ -50,8 +50,21 @@ int w1_max_slave_count = 64;
 int w1_max_slave_ttl = 10;
 
 module_param_named(timeout, w1_timeout, int, 0);
+MODULE_PARM_DESC(timeout, "time in seconds between automatic slave searches");
+/* A search stops when w1_max_slave_count devices have been found in that
+ * search.  The next search will start over and detect the same set of devices
+ * on a static 1-wire bus.  Memory is not allocated based on this number, just
+ * on the number of devices known to the kernel.  Having a high number does not
+ * consume additional resources.  As a special case, if there is only one
+ * device on the network and w1_max_slave_count is set to 1, the device id can
+ * be read directly skipping the normal slower search process.
+ */
 module_param_named(max_slave_count, w1_max_slave_count, int, 0);
+MODULE_PARM_DESC(max_slave_count,
+	"maximum number of slaves detected in a search");
 module_param_named(slave_ttl, w1_max_slave_ttl, int, 0);
+MODULE_PARM_DESC(slave_ttl,
+	"Number of searches not seeing a slave before it will be removed");
 
 DEFINE_MUTEX(w1_mlock);
 LIST_HEAD(w1_masters);

@@ -920,7 +933,12 @@ void w1_slave_found(struct w1_master *dev, u64 rn)
 }
 
 /**
- * Performs a ROM Search & registers any devices found.
+ * w1_search() - Performs a ROM Search & registers any devices found.
+ * @dev: The master device to search
+ * @search_type: W1_SEARCH to search all devices, or W1_ALARM_SEARCH
+ * to return only devices in the alarmed state
+ * @cb: Function to call when a device is found
+ *
  * The 1-wire search is a simple binary tree search.
  * For each bit of the address, we read two bits and write one bit.
  * The bit written will put to sleep all devies that don't match that bit.

@@ -930,8 +948,6 @@ void w1_slave_found(struct w1_master *dev, u64 rn)
  *
  * See "Application note 187 1-wire search algorithm" at www.maxim-ic.com
  *
- * @dev        The master device to search
- * @cb         Function to call when a device is found
  */
 void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb)
 {

@@ -990,7 +1006,7 @@ void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb
 			else
 				search_bit = ((last_rn >> i) & 0x1);
 
-			/** Read two bits and write one bit */
+			/* Read two bits and write one bit */
 			triplet_ret = w1_triplet(dev, search_bit);
 
 			/* quit if no device responded */

@@ -1074,6 +1090,12 @@ static void w1_search_process(struct w1_master *dev, u8 search_type)
 	w1_search_process_cb(dev, search_type, w1_slave_found);
 }
 
+/**
+ * w1_process_callbacks() - execute each dev->async_list callback entry
+ * @dev: w1_master device
+ *
+ * Return: 1 if there were commands to executed 0 otherwise
+ */
 int w1_process_callbacks(struct w1_master *dev)
 {
 	int ret = 0;

202 lines not on this page · raw message

index e9309778..3bff6b3 100644
@@ -31,6 +31,10 @@
 DEFINE_SPINLOCK(w1_flock);
 static LIST_HEAD(w1_families);
 
+/**
+ * w1_register_family() - register a device family driver
+ * @newf:	family to register
+ */
 int w1_register_family(struct w1_family *newf)
 {
 	struct list_head *ent, *n;

@@ -59,6 +63,10 @@ int w1_register_family(struct w1_family *newf)
 	return ret;
 }
 
+/**
+ * w1_unregister_family() - unregister a device family driver
+ * @fent:	family to unregister
+ */
 void w1_unregister_family(struct w1_family *fent)
 {
 	struct list_head *ent, *n;

index 4ad0e81..26ca134 100644
@@ -48,6 +48,12 @@
 
 struct w1_slave;
 
+/**
+ * struct w1_family_ops - operations for a family type
+ * @add_slave: add_slave
+ * @remove_slave: remove_slave
+ * @groups: sysfs group
+ */
 struct w1_family_ops
 {
 	int  (* add_slave)(struct w1_slave *);

@@ -55,6 +61,13 @@ struct w1_family_ops
 	const struct attribute_group **groups;
 };
 
+/**
+ * struct w1_family - reference counted family structure.
+ * @family_entry:	family linked list
+ * @fid:		8 bit family identifier
+ * @fops:		operations for this family
+ * @refcnt:		reference counter
+ */
 struct w1_family
 {
 	struct list_head	family_entry;

index 66b2caa..9b084db 100644
@@ -105,6 +105,10 @@ static void w1_free_dev(struct w1_master *dev)
 	device_unregister(&dev->dev);
 }
 
+/**
+ * w1_add_master_device() - registers a new master device
+ * @master:	master bus device to register
+ */
 int w1_add_master_device(struct w1_bus_master *master)
 {
 	struct w1_master *dev, *entry;

@@ -227,6 +231,10 @@ void __w1_remove_master_device(struct w1_master *dev)
 	w1_free_dev(dev);
 }
 
+/**
+ * w1_remove_master_device() - unregister a master device
+ * @bm:	master bus device to remove
+ */
 void w1_remove_master_device(struct w1_bus_master *bm)
 {
 	struct w1_master *dev, *found = NULL;

220 lines not on this page · raw message

index ea9f3e4..1e9504e 100644
@@ -27,7 +27,8 @@
 
 #include "w1.h"
 
-/** enum w1_netlink_message_types - message type
+/**
+ * enum w1_netlink_message_types - message type
  *
  * @W1_SLAVE_ADD: notification that a slave device was added
  * @W1_SLAVE_REMOVE: notification that a slave device was removed

@@ -63,7 +64,8 @@ struct w1_netlink_msg
 	__u8				data[0];
 };
 
-/** enum w1_commands - commands available for master or slave operations
+/**
+ * enum w1_commands - commands available for master or slave operations
  * @W1_CMD_READ: read len bytes
  * @W1_CMD_WRITE: write len bytes
  * @W1_CMD_SEARCH: initiate a standard search, returns only the slave

index 02df3b1..b077b8b 100644
@@ -326,13 +326,14 @@ static void ds1wm_search(void *data, struct w1_master *master_dev,
 	unsigned slaves_found = 0;
 	unsigned int pass = 0;
 
+	mutex_lock(&master_dev->bus_mutex);
 	dev_dbg(&ds1wm_data->pdev->dev, "search begin\n");
 	while (true) {
 		++pass;
 		if (pass > 100) {
 			dev_dbg(&ds1wm_data->pdev->dev,
 				"too many attempts (100), search aborted\n");
-			return;
+			break;
 		}
 
 		mutex_lock(&master_dev->bus_mutex);

@@ -439,6 +440,7 @@ static void ds1wm_search(void *data, struct w1_master *master_dev,
 	dev_dbg(&ds1wm_data->pdev->dev,
 		"pass: %d total: %d search done ms d bit pos: %d\n", pass,
 		slaves_found, ms_discrep_bit);
+	mutex_unlock(&master_dev->bus_mutex);
 }
 
 /* --------------------------------------------------------------------- */

index db0bf32..7404ad30 100644
@@ -727,9 +727,11 @@ static void ds9490r_search(void *data, struct w1_master *master,
 	 */
 	u64 buf[2*64/8];
 
+	mutex_lock(&master->bus_mutex);
+
 	/* address to start searching at */
 	if (ds_send_data(dev, (u8 *)&master->search_id, 8) < 0)
-		return;
+		goto search_out;
 	master->search_id = 0;
 
 	value = COMM_SEARCH_ACCESS | COMM_IM | COMM_RST | COMM_SM | COMM_F |

@@ -739,7 +741,7 @@ static void ds9490r_search(void *data, struct w1_master *master,
 		search_limit = 0;
 	index = search_type | (search_limit << 8);
 	if (ds_send_control(dev, value, index) < 0)
-		return;
+		goto search_out;
 
 	do {
 		schedule_timeout(jtime);

@@ -791,6 +793,8 @@ static void ds9490r_search(void *data, struct w1_master *master,
 			master->max_slave_count);
 		set_bit(W1_WARN_MAX_COUNT, &master->flags);
 	}
+search_out:
+	mutex_unlock(&master->bus_mutex);
 }
 
 #if 0

index a5dc219..5234964 100644
@@ -246,11 +246,16 @@ static int w1_process_command_master(struct w1_master *dev,
 {
 	int err = -EINVAL;
 
+	/* drop bus_mutex for search (does it's own locking), and add/remove
+	 * which doesn't use the bus
+	 */
 	switch (req_cmd->cmd) {
 	case W1_CMD_SEARCH:
 	case W1_CMD_ALARM_SEARCH:
 	case W1_CMD_LIST_SLAVES:
+		mutex_unlock(&dev->bus_mutex);
 		err = w1_get_slaves(dev, req_msg, req_hdr, req_cmd);
+		mutex_lock(&dev->bus_mutex);
 		break;
 	case W1_CMD_READ:
 	case W1_CMD_WRITE:

@@ -262,8 +267,12 @@ static int w1_process_command_master(struct w1_master *dev,
 		break;
 	case W1_CMD_SLAVE_ADD:
 	case W1_CMD_SLAVE_REMOVE:
+		mutex_unlock(&dev->bus_mutex);
+		mutex_lock(&dev->mutex);
 		err = w1_process_command_addremove(dev, req_msg, req_hdr,
 			req_cmd);
+		mutex_unlock(&dev->mutex);
+		mutex_lock(&dev->bus_mutex);
 		break;
 	default:
 		err = -EINVAL;

@@ -400,7 +409,7 @@ static void w1_process_cb(struct w1_master *dev, struct w1_async_cmd *async_cmd)
 	struct w1_slave *sl = node->sl;
 	struct w1_netlink_cmd *cmd = NULL;
 
-	mutex_lock(&dev->mutex);
+	mutex_lock(&dev->bus_mutex);
 	dev->portid = node->block->portid;
 	if (sl && w1_reset_select_slave(sl))
 		err = -ENODEV;

@@ -437,7 +446,7 @@ static void w1_process_cb(struct w1_master *dev, struct w1_async_cmd *async_cmd)
 	else
 		atomic_dec(&dev->refcnt);
 	dev->portid = 0;
-	mutex_unlock(&dev->mutex);
+	mutex_unlock(&dev->bus_mutex);
 
 	mutex_lock(&dev->list_mutex);
 	list_del(&async_cmd->async_entry);