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driver core: Make state_synced device attribute writeable

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If the file is written to and sync_state() hasn't been called for the
device yet, then call sync_state() for the device independent of the
state of its consumers.

This is useful for supplier devices that have one or more consumers that
don't have a driver but the consumers are in a state that don't use the
resources supplied by the supplier device.

This gives finer grained control than using the
fw_devlink.sync_state=timeout kernel commandline parameter.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20230304005355.746421-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Saravana Kannan 2023-03-03 16:53:54 -08:00 committed by Greg Kroah-Hartman
parent ffbe08a8e8
commit f8fb576658
4 changed files with 36 additions and 5 deletions
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5
Documentation/ABI/testing/sysfs-devices-state_synced
View File

@ -21,4 +21,9 @@ Description:
at the time the kernel starts are not affected or limited in
any way by sync_state() callbacks.
Writing "1" to this file will force a call to the device's
sync_state() function if it hasn't been called already. The
sync_state() call happens independent of the state of the
consumer devices.

8
drivers/base/base.h
View File

@ -164,6 +164,14 @@ static inline int driver_match_device(struct device_driver *drv,
return drv->bus->match ? drv->bus->match(dev, drv) : 1;
}
static inline void dev_sync_state(struct device *dev)
{
if (dev->bus->sync_state)
dev->bus->sync_state(dev);
else if (dev->driver && dev->driver->sync_state)
dev->driver->sync_state(dev);
}
extern int driver_add_groups(struct device_driver *drv,
const struct attribute_group **groups);
extern void driver_remove_groups(struct device_driver *drv,

5
drivers/base/core.c
View File

@ -1160,10 +1160,7 @@ static void device_links_flush_sync_list(struct list_head *list,
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);
dev_sync_state(dev);
if (dev != dont_lock_dev)
device_unlock(dev);

23
drivers/base/dd.c
View File

@ -510,6 +510,27 @@ EXPORT_SYMBOL_GPL(device_bind_driver);
static atomic_t probe_count = ATOMIC_INIT(0);
static DECLARE_WAIT_QUEUE_HEAD(probe_waitqueue);
static ssize_t state_synced_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
int ret = 0;
if (strcmp("1", buf))
return -EINVAL;
device_lock(dev);
if (!dev->state_synced) {
dev->state_synced = true;
dev_sync_state(dev);
} else {
ret = -EINVAL;
}
device_unlock(dev);
return ret ? ret : count;
}
static ssize_t state_synced_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@ -521,7 +542,7 @@ static ssize_t state_synced_show(struct device *dev,
return sysfs_emit(buf, "%u\n", val);
}
static DEVICE_ATTR_RO(state_synced);
static DEVICE_ATTR_RW(state_synced);
static void device_unbind_cleanup(struct device *dev)
{