From: Saravana Kannan <saravanak@google.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Saravana Kannan <saravanak@google.com>
Cc: kernel-team@android.com, linux-kernel@vger.kernel.org
Subject: [PATCH v1 1/3] driver core: Call sync_state() even if supplier has no consumers
Date: Thu, 20 Feb 2020 23:50:34 -0800 [thread overview]
Message-ID: <20200221075036.181885-2-saravanak@google.com> (raw)
In-Reply-To: <20200221075036.181885-1-saravanak@google.com>
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>
---
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)
--
2.25.0.265.gbab2e86ba0-goog
next prev parent reply other threads:[~2020-02-21 8:45 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-21 7:50 [PATCH v1 0/3] driver core: sync state fixups Saravana Kannan
2020-02-21 7:50 ` Saravana Kannan [this message]
2020-02-21 7:50 ` [PATCH v1 2/3] driver core: Add dev_has_sync_state() Saravana Kannan
2020-02-21 7:50 ` [PATCH v1 3/3] driver core: Skip unnecessary work when device doesn't have sync_state() Saravana Kannan
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