On Tue, 2012-10-23 at 21:10 +0800, Tang Chen wrote:
> As the comments in __acpi_os_execute() said:
>
> We can't run hotplug code in keventd_wq/kacpid_wq/kacpid_notify_wq
> because the hotplug code may call driver .remove() functions,
> which invoke flush_scheduled_work/acpi_os_wait_events_complete
> to flush these workqueues.
>
> we should keep the hotplug code in kacpi_hotplug_wq.
>
> But we have the following call series in kernel now:
> acpi_ev_queue_notify_request()
> |--> acpi_os_execute()
> |--> __acpi_os_execute(type, function, context, 0)
>
> The last parameter 0 makes the container_notify_cb() executed in
> kacpi_notify_wq or kacpid_wq. So, we need to put the real hotplug code
> into kacpi_hotplug_wq.
Hi Tang,
I am curious; is there a particular reason why you use
alloc_acpi_container_hp_work() instead of acpi_os_hotplug_execute(),
which is already there in the tree?
Thanks,
-Toshi
> Signed-off-by: Tang Chen <tangchen@xxxxxxxxxxxxxx>
> ---
> drivers/acpi/container.c | 44 +++++++++++++++++++++++++++++++++++++++++++-
> 1 files changed, 43 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/acpi/container.c b/drivers/acpi/container.c
> index 1f9f7d7..643657a 100644
> --- a/drivers/acpi/container.c
> +++ b/drivers/acpi/container.c
> @@ -72,8 +72,36 @@ static struct acpi_driver acpi_container_driver = {
> },
> };
>
> +struct acpi_container_hp_work {
> + struct work_struct work;
> + acpi_handle handle;
> + u32 type;
> + void *context;
> +};
> +
> /*******************************************************************/
>
> +static void alloc_acpi_container_hp_work(acpi_handle handle, u32 type,
> + void *context,
> + void (*func)(struct work_struct *work))
> +{
> + struct acpi_container_hp_work *hp_work;
> + int ret;
> +
> + hp_work = kmalloc(sizeof(*hp_work), GFP_KERNEL);
> + if (!hp_work)
> + return;
> +
> + hp_work->handle = handle;
> + hp_work->type = type;
> + hp_work->context = context;
> +
> + INIT_WORK(&hp_work->work, func);
> + ret = queue_work(kacpi_hotplug_wq, &hp_work->work);
> + if (!ret)
> + kfree(hp_work);
> +}
> +
> static int is_device_present(acpi_handle handle)
> {
> acpi_handle temp;
> @@ -152,14 +180,21 @@ static int container_device_add(struct acpi_device **device, acpi_handle handle)
> return result;
> }
>
> -static void container_notify_cb(acpi_handle handle, u32 type, void *context)
> +static void __container_notify_cb(struct work_struct *work)
> {
> struct acpi_device *device = NULL;
> int result;
> int present;
> acpi_status status;
> + struct acpi_container_hp_work *hp_work;
> + acpi_handle handle;
> + u32 type;
> u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
>
> + hp_work = container_of(work, struct acpi_container_hp_work, work);
> + handle = hp_work->handle;
> + type = hp_work->type;
> +
> switch (type) {
> case ACPI_NOTIFY_BUS_CHECK:
> /* Fall through */
> @@ -211,6 +246,13 @@ static void container_notify_cb(acpi_handle handle, u32 type, void *context)
> return;
> }
>
> +static void container_notify_cb(acpi_handle handle, u32 type,
> + void *context)
> +{
> + alloc_acpi_container_hp_work(handle, type, context,
> + __container_notify_cb);
> +}
> +
> static acpi_status
> container_walk_namespace_cb(acpi_handle handle,
> u32 lvl, void *context, void **rv)
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