Merge tag 'driver-core-5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fixes from Greg KH:
 "Here are some small driver core fixes for 5.11-rc5 that resolve some
  reported problems:

   - revert of a -rc1 patch that was causing problems with some machines

   - device link device name collision problem fix (busses only have to
     name devices unique to their bus, not unique to all busses)

   - kernfs splice bugfixes to resolve firmware loading problems for
     Qualcomm systems.

   - other tiny driver core fixes for minor issues reported.

  All of these have been in linux-next with no reported problems"

* tag 'driver-core-5.11-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  driver core: Fix device link device name collision
  driver core: Extend device_is_dependent()
  kernfs: wire up ->splice_read and ->splice_write
  kernfs: implement ->write_iter
  kernfs: implement ->read_iter
  Revert "driver core: Reorder devices on successful probe"
  Driver core: platform: Add extra error check in devm_platform_get_irqs_affinity()
  drivers core: Free dma_range_map when driver probe failed

1 files changed, 31 insertions, 13 deletions

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 14f165816742..6eb4c7a904c5 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -208,6 +208,16 @@ int device_links_read_lock_held(void)
 #endif
 #endif /* !CONFIG_SRCU */
 
+static bool device_is_ancestor(struct device *dev, struct device *target)
+{
+	while (target->parent) {
+		target = target->parent;
+		if (dev == target)
+			return true;
+	}
+	return false;
+}
+
 /**
  * device_is_dependent - Check if one device depends on another one
  * @dev: Device to check dependencies for.
@@ -221,7 +231,12 @@ int device_is_dependent(struct device *dev, void *target)
 	struct device_link *link;
 	int ret;
 
-	if (dev == target)
+	/*
+	 * The "ancestors" check is needed to catch the case when the target
+	 * device has not been completely initialized yet and it is still
+	 * missing from the list of children of its parent device.
+	 */
+	if (dev == target || device_is_ancestor(dev, target))
 		return 1;
 
 	ret = device_for_each_child(dev, target, device_is_dependent);
@@ -456,7 +471,9 @@ static int devlink_add_symlinks(struct device *dev,
 	struct device *con = link->consumer;
 	char *buf;
 
-	len = max(strlen(dev_name(sup)), strlen(dev_name(con)));
+	len = max(strlen(dev_bus_name(sup)) + strlen(dev_name(sup)),
+		  strlen(dev_bus_name(con)) + strlen(dev_name(con)));
+	len += strlen(":");
 	len += strlen("supplier:") + 1;
 	buf = kzalloc(len, GFP_KERNEL);
 	if (!buf)
@@ -470,12 +487,12 @@ static int devlink_add_symlinks(struct device *dev,
 	if (ret)
 		goto err_con;
 
-	snprintf(buf, len, "consumer:%s", dev_name(con));
+	snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), dev_name(con));
 	ret = sysfs_create_link(&sup->kobj, &link->link_dev.kobj, buf);
 	if (ret)
 		goto err_con_dev;
 
-	snprintf(buf, len, "supplier:%s", dev_name(sup));
+	snprintf(buf, len, "supplier:%s:%s", dev_bus_name(sup), dev_name(sup));
 	ret = sysfs_create_link(&con->kobj, &link->link_dev.kobj, buf);
 	if (ret)
 		goto err_sup_dev;
@@ -483,7 +500,7 @@ static int devlink_add_symlinks(struct device *dev,
 	goto out;
 
 err_sup_dev:
-	snprintf(buf, len, "consumer:%s", dev_name(con));
+	snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), dev_name(con));
 	sysfs_remove_link(&sup->kobj, buf);
 err_con_dev:
 	sysfs_remove_link(&link->link_dev.kobj, "consumer");
@@ -506,7 +523,9 @@ static void devlink_remove_symlinks(struct device *dev,
 	sysfs_remove_link(&link->link_dev.kobj, "consumer");
 	sysfs_remove_link(&link->link_dev.kobj, "supplier");
 
-	len = max(strlen(dev_name(sup)), strlen(dev_name(con)));
+	len = max(strlen(dev_bus_name(sup)) + strlen(dev_name(sup)),
+		  strlen(dev_bus_name(con)) + strlen(dev_name(con)));
+	len += strlen(":");
 	len += strlen("supplier:") + 1;
 	buf = kzalloc(len, GFP_KERNEL);
 	if (!buf) {
@@ -514,9 +533,9 @@ static void devlink_remove_symlinks(struct device *dev,
 		return;
 	}
 
-	snprintf(buf, len, "supplier:%s", dev_name(sup));
+	snprintf(buf, len, "supplier:%s:%s", dev_bus_name(sup), dev_name(sup));
 	sysfs_remove_link(&con->kobj, buf);
-	snprintf(buf, len, "consumer:%s", dev_name(con));
+	snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), dev_name(con));
 	sysfs_remove_link(&sup->kobj, buf);
 	kfree(buf);
 }
@@ -737,8 +756,9 @@ struct device_link *device_link_add(struct device *consumer,
 
 	link->link_dev.class = &devlink_class;
 	device_set_pm_not_required(&link->link_dev);
-	dev_set_name(&link->link_dev, "%s--%s",
-		     dev_name(supplier), dev_name(consumer));
+	dev_set_name(&link->link_dev, "%s:%s--%s:%s",
+		     dev_bus_name(supplier), dev_name(supplier),
+		     dev_bus_name(consumer), dev_name(consumer));
 	if (device_register(&link->link_dev)) {
 		put_device(consumer);
 		put_device(supplier);
@@ -1808,9 +1828,7 @@ const char *dev_driver_string(const struct device *dev)
 	 * never change once they are set, so they don't need special care.
 	 */
 	drv = READ_ONCE(dev->driver);
-	return drv ? drv->name :
-			(dev->bus ? dev->bus->name :
-			(dev->class ? dev->class->name : ""));
+	return drv ? drv->name : dev_bus_name(dev);
 }
 EXPORT_SYMBOL(dev_driver_string);