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-rw-r--r--drivers/base/Kconfig2
-rw-r--r--drivers/base/bus.c17
-rw-r--r--drivers/base/core.c101
3 files changed, 89 insertions, 31 deletions
diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index 040be48ce046..324aa03fed3c 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -161,7 +161,7 @@ config HMEM_REPORTING
default n
depends on NUMA
help
- Enable reporting for heterogenous memory access attributes under
+ Enable reporting for heterogeneous memory access attributes under
their non-uniform memory nodes.
source "drivers/base/test/Kconfig"
diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index a9c23ecebc7c..b48ad519c34e 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -729,23 +729,6 @@ int device_reprobe(struct device *dev)
}
EXPORT_SYMBOL_GPL(device_reprobe);
-/**
- * find_bus - locate bus by name.
- * @name: name of bus.
- *
- * Call kset_find_obj() to iterate over list of buses to
- * find a bus by name. Return bus if found.
- *
- * Note that kset_find_obj increments bus' reference count.
- */
-#if 0
-struct bus_type *find_bus(char *name)
-{
- struct kobject *k = kset_find_obj(bus_kset, name);
- return k ? to_bus(k) : NULL;
-}
-#endif /* 0 */
-
static int bus_add_groups(struct bus_type *bus,
const struct attribute_group **groups)
{
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 6eb4c7a904c5..484a942884ba 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -244,7 +244,8 @@ int device_is_dependent(struct device *dev, void *target)
return ret;
list_for_each_entry(link, &dev->links.consumers, s_node) {
- if (link->flags == (DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED))
+ if ((link->flags & ~DL_FLAG_INFERRED) ==
+ (DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED))
continue;
if (link->consumer == target)
@@ -317,7 +318,8 @@ static int device_reorder_to_tail(struct device *dev, void *not_used)
device_for_each_child(dev, NULL, device_reorder_to_tail);
list_for_each_entry(link, &dev->links.consumers, s_node) {
- if (link->flags == (DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED))
+ if ((link->flags & ~DL_FLAG_INFERRED) ==
+ (DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED))
continue;
device_reorder_to_tail(link->consumer, NULL);
}
@@ -565,7 +567,8 @@ postcore_initcall(devlink_class_init);
#define DL_MANAGED_LINK_FLAGS (DL_FLAG_AUTOREMOVE_CONSUMER | \
DL_FLAG_AUTOREMOVE_SUPPLIER | \
DL_FLAG_AUTOPROBE_CONSUMER | \
- DL_FLAG_SYNC_STATE_ONLY)
+ DL_FLAG_SYNC_STATE_ONLY | \
+ DL_FLAG_INFERRED)
#define DL_ADD_VALID_FLAGS (DL_MANAGED_LINK_FLAGS | DL_FLAG_STATELESS | \
DL_FLAG_PM_RUNTIME | DL_FLAG_RPM_ACTIVE)
@@ -634,7 +637,7 @@ struct device_link *device_link_add(struct device *consumer,
if (!consumer || !supplier || flags & ~DL_ADD_VALID_FLAGS ||
(flags & DL_FLAG_STATELESS && flags & DL_MANAGED_LINK_FLAGS) ||
(flags & DL_FLAG_SYNC_STATE_ONLY &&
- flags != DL_FLAG_SYNC_STATE_ONLY) ||
+ (flags & ~DL_FLAG_INFERRED) != DL_FLAG_SYNC_STATE_ONLY) ||
(flags & DL_FLAG_AUTOPROBE_CONSUMER &&
flags & (DL_FLAG_AUTOREMOVE_CONSUMER |
DL_FLAG_AUTOREMOVE_SUPPLIER)))
@@ -690,6 +693,10 @@ struct device_link *device_link_add(struct device *consumer,
if (link->consumer != consumer)
continue;
+ if (link->flags & DL_FLAG_INFERRED &&
+ !(flags & DL_FLAG_INFERRED))
+ link->flags &= ~DL_FLAG_INFERRED;
+
if (flags & DL_FLAG_PM_RUNTIME) {
if (!(link->flags & DL_FLAG_PM_RUNTIME)) {
pm_runtime_new_link(consumer);
@@ -949,6 +956,10 @@ int device_links_check_suppliers(struct device *dev)
mutex_lock(&fwnode_link_lock);
if (dev->fwnode && !list_empty(&dev->fwnode->suppliers) &&
!fw_devlink_is_permissive()) {
+ dev_dbg(dev, "probe deferral - wait for supplier %pfwP\n",
+ list_first_entry(&dev->fwnode->suppliers,
+ struct fwnode_link,
+ c_hook)->supplier);
mutex_unlock(&fwnode_link_lock);
return -EPROBE_DEFER;
}
@@ -963,6 +974,8 @@ int device_links_check_suppliers(struct device *dev)
if (link->status != DL_STATE_AVAILABLE &&
!(link->flags & DL_FLAG_SYNC_STATE_ONLY)) {
device_links_missing_supplier(dev);
+ dev_dbg(dev, "probe deferral - supplier %s not ready\n",
+ dev_name(link->supplier));
ret = -EPROBE_DEFER;
break;
}
@@ -1457,7 +1470,14 @@ static void device_links_purge(struct device *dev)
device_links_write_unlock();
}
-static u32 fw_devlink_flags = DL_FLAG_SYNC_STATE_ONLY;
+#define FW_DEVLINK_FLAGS_PERMISSIVE (DL_FLAG_INFERRED | \
+ DL_FLAG_SYNC_STATE_ONLY)
+#define FW_DEVLINK_FLAGS_ON (DL_FLAG_INFERRED | \
+ DL_FLAG_AUTOPROBE_CONSUMER)
+#define FW_DEVLINK_FLAGS_RPM (FW_DEVLINK_FLAGS_ON | \
+ DL_FLAG_PM_RUNTIME)
+
+static u32 fw_devlink_flags = FW_DEVLINK_FLAGS_ON;
static int __init fw_devlink_setup(char *arg)
{
if (!arg)
@@ -1466,12 +1486,11 @@ static int __init fw_devlink_setup(char *arg)
if (strcmp(arg, "off") == 0) {
fw_devlink_flags = 0;
} else if (strcmp(arg, "permissive") == 0) {
- fw_devlink_flags = DL_FLAG_SYNC_STATE_ONLY;
+ fw_devlink_flags = FW_DEVLINK_FLAGS_PERMISSIVE;
} else if (strcmp(arg, "on") == 0) {
- fw_devlink_flags = DL_FLAG_AUTOPROBE_CONSUMER;
+ fw_devlink_flags = FW_DEVLINK_FLAGS_ON;
} else if (strcmp(arg, "rpm") == 0) {
- fw_devlink_flags = DL_FLAG_AUTOPROBE_CONSUMER |
- DL_FLAG_PM_RUNTIME;
+ fw_devlink_flags = FW_DEVLINK_FLAGS_RPM;
}
return 0;
}
@@ -1484,7 +1503,7 @@ u32 fw_devlink_get_flags(void)
static bool fw_devlink_is_permissive(void)
{
- return fw_devlink_flags == DL_FLAG_SYNC_STATE_ONLY;
+ return fw_devlink_flags == FW_DEVLINK_FLAGS_PERMISSIVE;
}
static void fw_devlink_parse_fwnode(struct fwnode_handle *fwnode)
@@ -1507,6 +1526,53 @@ static void fw_devlink_parse_fwtree(struct fwnode_handle *fwnode)
}
/**
+ * fw_devlink_relax_cycle - Convert cyclic links to SYNC_STATE_ONLY links
+ * @con: Device to check dependencies for.
+ * @sup: Device to check against.
+ *
+ * Check if @sup depends on @con or any device dependent on it (its child or
+ * its consumer etc). When such a cyclic dependency is found, convert all
+ * device links created solely by fw_devlink into SYNC_STATE_ONLY device links.
+ * This is the equivalent of doing fw_devlink=permissive just between the
+ * devices in the cycle. We need to do this because, at this point, fw_devlink
+ * can't tell which of these dependencies is not a real dependency.
+ *
+ * Return 1 if a cycle is found. Otherwise, return 0.
+ */
+static int fw_devlink_relax_cycle(struct device *con, void *sup)
+{
+ struct device_link *link;
+ int ret;
+
+ if (con == sup)
+ return 1;
+
+ ret = device_for_each_child(con, sup, fw_devlink_relax_cycle);
+ if (ret)
+ return ret;
+
+ list_for_each_entry(link, &con->links.consumers, s_node) {
+ if ((link->flags & ~DL_FLAG_INFERRED) ==
+ (DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED))
+ continue;
+
+ if (!fw_devlink_relax_cycle(link->consumer, sup))
+ continue;
+
+ 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));
+ }
+ 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
@@ -1537,8 +1603,17 @@ static int fw_devlink_create_devlink(struct device *con,
* If this fails, it is due to cycles in device links. Just
* give up on this link and treat it as invalid.
*/
- if (!device_link_add(con, sup_dev, flags))
+ if (!device_link_add(con, sup_dev, flags) &&
+ !(flags & DL_FLAG_SYNC_STATE_ONLY)) {
+ dev_info(con, "Fixing up cyclic dependency with %s\n",
+ dev_name(sup_dev));
+ device_links_write_lock();
+ fw_devlink_relax_cycle(con, sup_dev);
+ device_links_write_unlock();
+ device_link_add(con, sup_dev,
+ FW_DEVLINK_FLAGS_PERMISSIVE);
ret = -EINVAL;
+ }
goto out;
}
@@ -1631,7 +1706,7 @@ static void __fw_devlink_link_to_consumers(struct device *dev)
con_dev = NULL;
} else {
own_link = false;
- dl_flags = DL_FLAG_SYNC_STATE_ONLY;
+ dl_flags = FW_DEVLINK_FLAGS_PERMISSIVE;
}
}
@@ -1686,7 +1761,7 @@ static void __fw_devlink_link_to_suppliers(struct device *dev,
if (own_link)
dl_flags = fw_devlink_get_flags();
else
- dl_flags = DL_FLAG_SYNC_STATE_ONLY;
+ dl_flags = FW_DEVLINK_FLAGS_PERMISSIVE;
list_for_each_entry_safe(link, tmp, &fwnode->suppliers, c_hook) {
int ret;