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authorLinus Torvalds <torvalds@linux-foundation.org>2021-04-26 11:05:36 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-04-26 11:05:36 -0700
commitc01c0716ccf5db2086d9693033472f37de96a699 (patch)
tree330fbb4c8a386073a25fb17ee29be15e21266ab3 /drivers/base/core.c
parent8e3a3249502d8ff92d73d827fb41dd44c5a16f76 (diff)
parenta943d76352dbb4707a5e5537bbe696c00f5ddd36 (diff)
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Merge tag 'driver-core-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH: "Here is the "big" set of driver core changes for 5.13-rc1. Nothing major, just lots of little core changes and cleanups, notable things are: - finally set 'fw_devlink=on' by default. All reported issues with this have been shaken out over the past 9 months or so, but we will be paying attention to any fallout here in case we need to revert this as the default boot value (symptoms of problems are a simple lack of booting) - fixes found to be needed by fw_devlink=on value in some subsystems (like clock). - delayed work initialization cleanup - driver core cleanups and minor updates - software node cleanups and tweaks - devtmpfs cleanups - minor debugfs cleanups All of these have been in linux-next for a while with no reported issues" * tag 'driver-core-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (53 commits) devm-helpers: Fix devm_delayed_work_autocancel() kerneldoc PM / wakeup: use dev_set_name() directly software node: Allow node addition to already existing device kunit: software node: adhear to KUNIT formatting standard node: fix device cleanups in error handling code kobject_uevent: remove warning in init_uevent_argv() debugfs: Make debugfs_allow RO after init Revert "driver core: platform: Make platform_get_irq_optional() optional" media: ipu3-cio2: Switch to use SOFTWARE_NODE_REFERENCE() software node: Introduce SOFTWARE_NODE_REFERENCE() helper macro software node: Imply kobj_to_swnode() to be no-op software node: Deduplicate code in fwnode_create_software_node() software node: Introduce software_node_alloc()/software_node_free() software node: Free resources explicitly when swnode_register() fails debugfs: drop pointless nul-termination in debugfs_read_file_bool() driver core: add helper for deferred probe reason setting driver core: Improve fw_devlink & deferred_probe_timeout interaction of: property: fw_devlink: Add support for remote-endpoint driver core: platform: Make platform_get_irq_optional() optional driver core: Replace printf() specifier and drop unneeded casting ...
Diffstat (limited to 'drivers/base/core.c')
-rw-r--r--drivers/base/core.c112
1 files changed, 99 insertions, 13 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c
index f29839382f81..4a8bf8cda52b 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -51,6 +51,7 @@ static LIST_HEAD(deferred_sync);
static unsigned int defer_sync_state_count = 1;
static DEFINE_MUTEX(fwnode_link_lock);
static bool fw_devlink_is_permissive(void);
+static bool fw_devlink_drv_reg_done;
/**
* fwnode_link_add - Create a link between two fwnode_handles.
@@ -1154,6 +1155,41 @@ static ssize_t waiting_for_supplier_show(struct device *dev,
static DEVICE_ATTR_RO(waiting_for_supplier);
/**
+ * device_links_force_bind - Prepares device to be force bound
+ * @dev: Consumer device.
+ *
+ * device_bind_driver() force binds a device to a driver without calling any
+ * driver probe functions. So the consumer really isn't going to wait for any
+ * supplier before it's bound to the driver. We still want the device link
+ * states to be sensible when this happens.
+ *
+ * In preparation for device_bind_driver(), this function goes through each
+ * supplier device links and checks if the supplier is bound. If it is, then
+ * the device link status is set to CONSUMER_PROBE. Otherwise, the device link
+ * is dropped. Links without the DL_FLAG_MANAGED flag set are ignored.
+ */
+void device_links_force_bind(struct device *dev)
+{
+ struct device_link *link, *ln;
+
+ device_links_write_lock();
+
+ list_for_each_entry_safe(link, ln, &dev->links.suppliers, c_node) {
+ if (!(link->flags & DL_FLAG_MANAGED))
+ continue;
+
+ if (link->status != DL_STATE_AVAILABLE) {
+ device_link_drop_managed(link);
+ continue;
+ }
+ WRITE_ONCE(link->status, DL_STATE_CONSUMER_PROBE);
+ }
+ dev->links.status = DL_DEV_PROBING;
+
+ device_links_write_unlock();
+}
+
+/**
* device_links_driver_bound - Update device links after probing its driver.
* @dev: Device to update the links for.
*
@@ -1503,7 +1539,7 @@ static void device_links_purge(struct device *dev)
#define FW_DEVLINK_FLAGS_RPM (FW_DEVLINK_FLAGS_ON | \
DL_FLAG_PM_RUNTIME)
-static u32 fw_devlink_flags = FW_DEVLINK_FLAGS_PERMISSIVE;
+static u32 fw_devlink_flags = FW_DEVLINK_FLAGS_ON;
static int __init fw_devlink_setup(char *arg)
{
if (!arg)
@@ -1563,6 +1599,52 @@ static void fw_devlink_parse_fwtree(struct fwnode_handle *fwnode)
fw_devlink_parse_fwtree(child);
}
+static void fw_devlink_relax_link(struct device_link *link)
+{
+ if (!(link->flags & DL_FLAG_INFERRED))
+ return;
+
+ if (link->flags == (DL_FLAG_MANAGED | FW_DEVLINK_FLAGS_PERMISSIVE))
+ return;
+
+ pm_runtime_drop_link(link);
+ link->flags = DL_FLAG_MANAGED | FW_DEVLINK_FLAGS_PERMISSIVE;
+ dev_dbg(link->consumer, "Relaxing link with %s\n",
+ dev_name(link->supplier));
+}
+
+static int fw_devlink_no_driver(struct device *dev, void *data)
+{
+ struct device_link *link = to_devlink(dev);
+
+ if (!link->supplier->can_match)
+ fw_devlink_relax_link(link);
+
+ return 0;
+}
+
+void fw_devlink_drivers_done(void)
+{
+ fw_devlink_drv_reg_done = true;
+ device_links_write_lock();
+ class_for_each_device(&devlink_class, NULL, NULL,
+ fw_devlink_no_driver);
+ device_links_write_unlock();
+}
+
+static void fw_devlink_unblock_consumers(struct device *dev)
+{
+ struct device_link *link;
+
+ if (!fw_devlink_flags || fw_devlink_is_permissive())
+ return;
+
+ device_links_write_lock();
+ list_for_each_entry(link, &dev->links.consumers, s_node)
+ fw_devlink_relax_link(link);
+ device_links_write_unlock();
+}
+
/**
* fw_devlink_relax_cycle - Convert cyclic links to SYNC_STATE_ONLY links
* @con: Device to check dependencies for.
@@ -1599,21 +1681,16 @@ static int fw_devlink_relax_cycle(struct device *con, void *sup)
ret = 1;
- if (!(link->flags & DL_FLAG_INFERRED))
- continue;
-
- pm_runtime_drop_link(link);
- link->flags = DL_FLAG_MANAGED | FW_DEVLINK_FLAGS_PERMISSIVE;
- dev_dbg(link->consumer, "Relaxing link with %s\n",
- dev_name(link->supplier));
+ fw_devlink_relax_link(link);
}
return ret;
}
/**
* fw_devlink_create_devlink - Create a device link from a consumer to fwnode
- * @con - Consumer device for the device link
- * @sup_handle - fwnode handle of supplier
+ * @con: consumer device for the device link
+ * @sup_handle: fwnode handle of supplier
+ * @flags: devlink flags
*
* This function will try to create a device link between the consumer device
* @con and the supplier device represented by @sup_handle.
@@ -1709,7 +1786,7 @@ out:
/**
* __fw_devlink_link_to_consumers - Create device links to consumers of a device
- * @dev - Device that needs to be linked to its consumers
+ * @dev: Device that needs to be linked to its consumers
*
* This function looks at all the consumer fwnodes of @dev and creates device
* links between the consumer device and @dev (supplier).
@@ -1779,8 +1856,8 @@ static void __fw_devlink_link_to_consumers(struct device *dev)
/**
* __fw_devlink_link_to_suppliers - Create device links to suppliers of a device
- * @dev - The consumer device that needs to be linked to its suppliers
- * @fwnode - Root of the fwnode tree that is used to create device links
+ * @dev: The consumer device that needs to be linked to its suppliers
+ * @fwnode: Root of the fwnode tree that is used to create device links
*
* This function looks at all the supplier fwnodes of fwnode tree rooted at
* @fwnode and creates device links between @dev (consumer) and all the
@@ -3240,6 +3317,15 @@ int device_add(struct device *dev)
}
bus_probe_device(dev);
+
+ /*
+ * If all driver registration is done and a newly added device doesn't
+ * match with any driver, don't block its consumers from probing in
+ * case the consumer device is able to operate without this supplier.
+ */
+ if (dev->fwnode && fw_devlink_drv_reg_done && !dev->can_match)
+ fw_devlink_unblock_consumers(dev);
+
if (parent)
klist_add_tail(&dev->p->knode_parent,
&parent->p->klist_children);