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authorLinus Torvalds <torvalds@linux-foundation.org>2020-03-08 16:39:40 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2020-03-08 16:39:40 +0100
commitb34e5c13327ef723362c88c43da176a439badeea (patch)
tree01c2f2ecee284b0f8ee098bd2af3c54ff91b067b
parentMerge tag 'tty-5.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/greg... (diff)
parentdriver core: Skip unnecessary work when device doesn't have sync_state() (diff)
downloadlinux-b34e5c13327ef723362c88c43da176a439badeea.tar.xz
linux-b34e5c13327ef723362c88c43da176a439badeea.zip
Merge tag 'driver-core-5.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core and debugfs fixes from Greg KH: "Here are four small driver core / debugfs patches for 5.6-rc3: - debugfs api cleanup now that all debugfs_create_regset32() callers have been fixed up. This was waiting until after the -rc1 merge as these fixes came in through different trees - driver core sync state fixes based on reports of minor issues found in the feature All of these have been in linux-next with no reported issues" * tag 'driver-core-5.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: driver core: Skip unnecessary work when device doesn't have sync_state() driver core: Add dev_has_sync_state() driver core: Call sync_state() even if supplier has no consumers debugfs: remove return value of debugfs_create_regset32()
-rw-r--r--Documentation/filesystems/debugfs.txt6
-rw-r--r--drivers/base/core.c27
-rw-r--r--fs/debugfs/file.c17
-rw-r--r--include/linux/debugfs.h13
-rw-r--r--include/linux/device.h11
5 files changed, 44 insertions, 30 deletions
diff --git a/Documentation/filesystems/debugfs.txt b/Documentation/filesystems/debugfs.txt
index dc497b96fa4f..55336a47a110 100644
--- a/Documentation/filesystems/debugfs.txt
+++ b/Documentation/filesystems/debugfs.txt
@@ -164,9 +164,9 @@ file.
void __iomem *base;
};
- struct dentry *debugfs_create_regset32(const char *name, umode_t mode,
- struct dentry *parent,
- struct debugfs_regset32 *regset);
+ debugfs_create_regset32(const char *name, umode_t mode,
+ struct dentry *parent,
+ struct debugfs_regset32 *regset);
void debugfs_print_regs32(struct seq_file *s, struct debugfs_reg32 *regs,
int nregs, void __iomem *base, char *prefix);
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 42a672456432..dbb0f9130f42 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -718,6 +718,8 @@ static void __device_links_queue_sync_state(struct device *dev,
{
struct device_link *link;
+ if (!dev_has_sync_state(dev))
+ return;
if (dev->state_synced)
return;
@@ -745,25 +747,31 @@ static void __device_links_queue_sync_state(struct device *dev,
/**
* device_links_flush_sync_list - Call sync_state() on a list of devices
* @list: List of devices to call sync_state() on
+ * @dont_lock_dev: Device for which lock is already held by the caller
*
* Calls sync_state() on all the devices that have been queued for it. This
- * function is used in conjunction with __device_links_queue_sync_state().
+ * function is used in conjunction with __device_links_queue_sync_state(). The
+ * @dont_lock_dev parameter is useful when this function is called from a
+ * context where a device lock is already held.
*/
-static void device_links_flush_sync_list(struct list_head *list)
+static void device_links_flush_sync_list(struct list_head *list,
+ struct device *dont_lock_dev)
{
struct device *dev, *tmp;
list_for_each_entry_safe(dev, tmp, list, links.defer_sync) {
list_del_init(&dev->links.defer_sync);
- device_lock(dev);
+ if (dev != dont_lock_dev)
+ device_lock(dev);
if (dev->bus->sync_state)
dev->bus->sync_state(dev);
else if (dev->driver && dev->driver->sync_state)
dev->driver->sync_state(dev);
- device_unlock(dev);
+ if (dev != dont_lock_dev)
+ device_unlock(dev);
put_device(dev);
}
@@ -801,7 +809,7 @@ void device_links_supplier_sync_state_resume(void)
out:
device_links_write_unlock();
- device_links_flush_sync_list(&sync_list);
+ device_links_flush_sync_list(&sync_list, NULL);
}
static int sync_state_resume_initcall(void)
@@ -813,7 +821,7 @@ late_initcall(sync_state_resume_initcall);
static void __device_links_supplier_defer_sync(struct device *sup)
{
- if (list_empty(&sup->links.defer_sync))
+ if (list_empty(&sup->links.defer_sync) && dev_has_sync_state(sup))
list_add_tail(&sup->links.defer_sync, &deferred_sync);
}
@@ -865,6 +873,11 @@ void device_links_driver_bound(struct device *dev)
driver_deferred_probe_add(link->consumer);
}
+ if (defer_sync_state_count)
+ __device_links_supplier_defer_sync(dev);
+ else
+ __device_links_queue_sync_state(dev, &sync_list);
+
list_for_each_entry(link, &dev->links.suppliers, c_node) {
if (!(link->flags & DL_FLAG_MANAGED))
continue;
@@ -883,7 +896,7 @@ void device_links_driver_bound(struct device *dev)
device_links_write_unlock();
- device_links_flush_sync_list(&sync_list);
+ device_links_flush_sync_list(&sync_list, dev);
}
static void device_link_drop_managed(struct device_link *link)
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index 634b09d18b77..db987b5110a9 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -1090,21 +1090,12 @@ static const struct file_operations fops_regset32 = {
* This function creates a file in debugfs with the given name that reports
* the names and values of a set of 32-bit registers. If the @mode variable
* is so set it can be read from. Writing is not supported.
- *
- * This function will return a pointer to a dentry if it succeeds. This
- * pointer must be passed to the debugfs_remove() function when the file is
- * to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.) If an error occurs, ERR_PTR(-ERROR) will be
- * returned.
- *
- * If debugfs is not enabled in the kernel, the value ERR_PTR(-ENODEV) will
- * be returned.
*/
-struct dentry *debugfs_create_regset32(const char *name, umode_t mode,
- struct dentry *parent,
- struct debugfs_regset32 *regset)
+void debugfs_create_regset32(const char *name, umode_t mode,
+ struct dentry *parent,
+ struct debugfs_regset32 *regset)
{
- return debugfs_create_file(name, mode, parent, regset, &fops_regset32);
+ debugfs_create_file(name, mode, parent, regset, &fops_regset32);
}
EXPORT_SYMBOL_GPL(debugfs_create_regset32);
diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h
index 3d013de64f70..43efcc49f061 100644
--- a/include/linux/debugfs.h
+++ b/include/linux/debugfs.h
@@ -127,9 +127,9 @@ struct dentry *debugfs_create_blob(const char *name, umode_t mode,
struct dentry *parent,
struct debugfs_blob_wrapper *blob);
-struct dentry *debugfs_create_regset32(const char *name, umode_t mode,
- struct dentry *parent,
- struct debugfs_regset32 *regset);
+void debugfs_create_regset32(const char *name, umode_t mode,
+ struct dentry *parent,
+ struct debugfs_regset32 *regset);
void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
int nregs, void __iomem *base, char *prefix);
@@ -304,11 +304,10 @@ static inline struct dentry *debugfs_create_blob(const char *name, umode_t mode,
return ERR_PTR(-ENODEV);
}
-static inline struct dentry *debugfs_create_regset32(const char *name,
- umode_t mode, struct dentry *parent,
- struct debugfs_regset32 *regset)
+static inline void debugfs_create_regset32(const char *name, umode_t mode,
+ struct dentry *parent,
+ struct debugfs_regset32 *regset)
{
- return ERR_PTR(-ENODEV);
}
static inline void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
diff --git a/include/linux/device.h b/include/linux/device.h
index 0cd7c647c16c..fa04dfd22bbc 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -798,6 +798,17 @@ static inline struct device_node *dev_of_node(struct device *dev)
return dev->of_node;
}
+static inline bool dev_has_sync_state(struct device *dev)
+{
+ if (!dev)
+ return false;
+ if (dev->driver && dev->driver->sync_state)
+ return true;
+ if (dev->bus && dev->bus->sync_state)
+ return true;
+ return false;
+}
+
/*
* High level routines for use by the bus drivers
*/