Re: [PATCH 1/2] Use kacpi_hotplug_wq to handle container hotplug event.
From: Toshi Kani <hidden>
Date: 2012-10-24 17:40:56
Also in:
linux-pci, lkml
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
quoted hunk ↗ jump to hunk
Signed-off-by: Tang Chen <redacted> --- 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)