From: David Daney <david.daney@xxxxxxxxxx>
Date: Thu, 7 Dec 2017 16:09:33 -0800
> +static void bgx_port_check_state(struct work_struct *work)
> +{
...
> + mutex_lock(&priv->lock);
> + if (priv->work_queued)
> + queue_delayed_work(check_state_wq, &priv->dwork, HZ);
> + mutex_unlock(&priv->lock);
> +}
...
> +int bgx_port_disable(struct net_device *netdev)
> +{
...
> + mutex_lock(&priv->lock);
> + if (priv->work_queued) {
> + cancel_delayed_work_sync(&priv->dwork);
> + priv->work_queued = false;
This can deadlock.
When you do a sync work cancel, it waits until all running work
instances finish. You have the priv->lock, so if
bgx_port_check_status() need to still take priv->lock to complete
then no further progress will be made.
I think it is pointless to use this weird work_queued boolean state.
Just unconditionally, and without locking, cancel the delayed work,
ragardless of whether it was actually used ever or not.
Thank you.
