On Mon, May 14, 2018 at 10:42 PM, Pavel Tatashin
<pasha.tatas...@oracle.com> wrote:
> #include <linux/netdevice.h>
> #include <linux/sched/signal.h>
> #include <linux/sysfs.h>
> +#include <linux/kthread.h>
Can we still preserve an order here? (Yes, even if the entire list is
not fully ordered)
In the context I see it would go before netdevice.h.
> +/**
> + * device_get_child_by_index - Return child using the provided index.
> + * @parent: parent struct device.
> + * @index: Index of the child, where 0 is the first child in the children
> list,
> + * and so on.
> + *
> + * Returns child or NULL if child with this index is not present.
> + */
> +static struct device *
> +device_get_child_by_index(struct device *parent, int index)
> +{
> + struct klist_iter i;
> + struct device *dev = NULL, *d;
> + int child_index = 0;
> +
> + if (!parent->p || index < 0)
> + return NULL;
> +
> + klist_iter_init(&parent->p->klist_children, &i);
> + while ((d = next_device(&i))) {
> + if (child_index == index) {
> + dev = d;
> + break;
> + }
> + child_index++;
> + }
> + klist_iter_exit(&i);
> +
> + return dev;
> +}
This can be implemented as a subfunction to device_find_child(), can't it be?
> +/**
Hmm... Why it's marked as kernel doc while it's just a plain comment?
Same applies to the rest of similar comments.
> + * Shutdown device tree with root started in dev. If dev has no children
> + * simply shutdown only this device. If dev has children recursively shutdown
> + * children first, and only then the parent. For performance reasons children
> + * are shutdown in parallel using kernel threads. because we lock dev its
> + * children cannot be removed while this functions is running.
> + */
> +static void device_shutdown_tree(struct device *dev)
> +{
> + int children_count;
> +
> + device_lock(dev);
> + children_count = device_children_count(dev);
> +
> + if (children_count) {
> + struct device_shutdown_task_data tdata;
> + int i;
> +
> + init_completion(&tdata.complete);
> + atomic_set(&tdata.child_next_index, 0);
> + atomic_set(&tdata.tasks_running, children_count);
> + tdata.parent = dev;
> +
> + for (i = 0; i < children_count; i++) {
> + if (device_shutdown_serial) {
> + device_shutdown_child_task(&tdata);
> + } else {
> + kthread_run(device_shutdown_child_task,
> + &tdata, "device_shutdown.%s",
> + dev_name(dev));
> + }
> + }
Can't we just use device_for_each_child() instead?
> + wait_for_completion(&tdata.complete);
> + }
> + device_shutdown_one(dev);
> + device_unlock(dev);
> +}
--
With Best Regards,
Andy Shevchenko
