This is a note to let you know that I've just added the patch titled
driver core: Call sync_state() even if supplier has no consumers
to my driver-core git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git in the driver-core-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
From 21eb93f432b1a785df193df1a56a59e9eb3a985f Mon Sep 17 00:00:00 2001
From: Saravana Kannan saravanak@google.com Date: Fri, 21 Feb 2020 00:05:08 -0800 Subject: driver core: Call sync_state() even if supplier has no consumers
The initial patch that added sync_state() support didn't handle the case where a supplier has no consumers. This was because when a device is successfully bound with a driver, only its suppliers were checked to see if they are eligible to get a sync_state(). This is not sufficient for devices that have no consumers but still need to do device state clean up. So fix this.
Fixes: fc5a251d0fd7ca90 (driver core: Add sync_state driver/bus callback) Signed-off-by: Saravana Kannan saravanak@google.com Cc: stable stable@vger.kernel.org Link: https://lore.kernel.org/r/20200221080510.197337-2-saravanak@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/base/core.c | 23 +++++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-)
diff --git a/drivers/base/core.c b/drivers/base/core.c index 42a672456432..3306d5ae92a6 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -745,25 +745,31 @@ 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 +807,7 @@ 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) @@ -865,6 +871,11 @@ 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 +894,7 @@ 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)