\AMW0.WMBC, which is the main method that we use,
is not reentrant. When wireless hotpluging is enabled,
toggling the status of the wireless device using WMBC will
trigger a notification and the notification handler need to
call WMBC again to get the new status of the device, this
will trigger the following error:
ACPI Error (dswload-0802): [_T_0] Namespace lookup failure, AE_ALREADY_EXISTS
ACPI Exception: AE_ALREADY_EXISTS, During name lookup/catalog (20100428/psloop-231)
ACPI Error (psparse-0537): Method parse/execution failed [\AMW0.WMBC] (Node f7023b88), AE_ALREADY_EXISTS
ACPI: Marking method WMBC as Serialized because of AE_ALREADY_EXISTS error
Since there is currently no way to tell the acpi subsystem to mark
a method as serialized, we do it in eeepc-wmi.
Of course, we could let the first call fail, and then it would work,
but it doesn't seems really clean, and it will make the first
WMBC call return a random value.
This patch was tested on EeePc 1000H with a RaLink RT2860
wireless card using the rt2800pci driver. rt2860sta driver
seems to deadlock when we remove the pci device...
Signed-off-by: Corentin Chary <corentincj@xxxxxxxxxx>
---
drivers/platform/x86/eeepc-wmi.c | 78 +++++++++++++++++++++++++++++++++++---
1 files changed, 72 insertions(+), 6 deletions(-)
diff --git a/drivers/platform/x86/eeepc-wmi.c b/drivers/platform/x86/eeepc-wmi.c
index 01bc2b3..eb4c0ce 100644
--- a/drivers/platform/x86/eeepc-wmi.c
+++ b/drivers/platform/x86/eeepc-wmi.c
@@ -137,6 +137,9 @@ struct eeepc_wmi {
struct hotplug_slot *hotplug_slot;
struct mutex hotplug_lock;
+ struct mutex wmi_lock;
+ struct workqueue_struct *hotplug_workqueue;
+ struct work_struct hotplug_work;
struct eeepc_wmi_debug debug;
};
@@ -370,15 +373,19 @@ static void eeepc_rfkill_hotplug(struct eeepc_wmi *eeepc)
{
struct pci_dev *dev;
struct pci_bus *bus;
- bool blocked = eeepc_wlan_rfkill_blocked(eeepc);
+ bool blocked;
bool absent;
u32 l;
- if (eeepc->wlan_rfkill)
- rfkill_set_sw_state(eeepc->wlan_rfkill, blocked);
+ mutex_lock(&eeepc->wmi_lock);
+ blocked = eeepc_wlan_rfkill_blocked(eeepc);
+ mutex_unlock(&eeepc->wmi_lock);
mutex_lock(&eeepc->hotplug_lock);
+ if (eeepc->wlan_rfkill)
+ rfkill_set_sw_state(eeepc->wlan_rfkill, blocked);
+
if (eeepc->hotplug_slot) {
bus = pci_find_bus(0, 1);
if (!bus) {
@@ -435,7 +442,14 @@ static void eeepc_rfkill_notify(acpi_handle handle, u32 event, void *data)
if (event != ACPI_NOTIFY_BUS_CHECK)
return;
- eeepc_rfkill_hotplug(eeepc);
+ /*
+ * We can't call directly eeepc_rfkill_hotplug because most
+ * of the time WMBC is still being executed and not reetrant.
+ * There is currently no way to tell ACPICA that we want this
+ * method to be serialized, we schedule a eeepc_rfkill_hotplug
+ * call later, in a safer context.
+ */
+ queue_work(eeepc->hotplug_workqueue, &eeepc->hotplug_work);
}
static int eeepc_register_rfkill_notifier(struct eeepc_wmi *eeepc,
@@ -508,6 +522,14 @@ static struct hotplug_slot_ops eeepc_hotplug_slot_ops = {
.get_power_status = eeepc_get_adapter_status,
};
+static void eeepc_hotplug_work(struct work_struct *work)
+{
+ struct eeepc_wmi *eeepc;
+
+ eeepc = container_of(work, struct eeepc_wmi, hotplug_work);
+ eeepc_rfkill_hotplug(eeepc);
+}
+
static int eeepc_setup_pci_hotplug(struct eeepc_wmi *eeepc)
{
int ret = -ENOMEM;
@@ -518,6 +540,13 @@ static int eeepc_setup_pci_hotplug(struct eeepc_wmi *eeepc)
return -ENODEV;
}
+ eeepc->hotplug_workqueue =
+ create_singlethread_workqueue("hotplug_workqueue");
+ if (!eeepc->hotplug_workqueue)
+ goto error_workqueue;
+
+ INIT_WORK(&eeepc->hotplug_work, eeepc_hotplug_work);
+
eeepc->hotplug_slot = kzalloc(sizeof(struct hotplug_slot), GFP_KERNEL);
if (!eeepc->hotplug_slot)
goto error_slot;
@@ -547,6 +576,8 @@ error_info:
kfree(eeepc->hotplug_slot);
eeepc->hotplug_slot = NULL;
error_slot:
+ destroy_workqueue(eeepc->hotplug_workqueue);
+error_workqueue:
return ret;
}
@@ -575,6 +606,34 @@ static void eeepc_rfkill_query(struct rfkill *rfkill, void *data)
rfkill_set_sw_state(rfkill, !(retval & 0x1));
}
+static int eeepc_rfkill_wlan_set(void *data, bool blocked)
+{
+ struct eeepc_wmi *eeepc = data;
+ int ret;
+
+ /*
+ * This handler is enabled only if hotplug is enabled.
+ * In this case, the eeepc_wmi_set_devstate() will
+ * trigger a wmi notification and we need to wait
+ * this call to finish before being able to call
+ * any wmi method
+ */
+ mutex_lock(&eeepc->wmi_lock);
+ ret = eeepc_rfkill_set((void *)(long)EEEPC_WMI_DEVID_WLAN, blocked);
+ mutex_unlock(&eeepc->wmi_lock);
+ return ret;
+}
+
+static void eeepc_rfkill_wlan_query(struct rfkill *rfkill, void *data)
+{
+ eeepc_rfkill_query(rfkill, (void *)(long)EEEPC_WMI_DEVID_WLAN);
+}
+
+static const struct rfkill_ops eeepc_rfkill_wlan_ops = {
+ .set_block = eeepc_rfkill_wlan_set,
+ .query = eeepc_rfkill_wlan_query,
+};
+
static const struct rfkill_ops eeepc_rfkill_ops = {
.set_block = eeepc_rfkill_set,
.query = eeepc_rfkill_query,
@@ -603,8 +662,12 @@ static int eeepc_new_rfkill(struct eeepc_wmi *eeepc,
if (!retval || retval == 0x00060000)
return -ENODEV;
- *rfkill = rfkill_alloc(name, &eeepc->platform_device->dev, type,
- &eeepc_rfkill_ops, (void *)(long)dev_id);
+ if (dev_id == EEEPC_WMI_DEVID_WLAN && eeepc->hotplug_wireless)
+ *rfkill = rfkill_alloc(name, &eeepc->platform_device->dev, type,
+ &eeepc_rfkill_wlan_ops, eeepc);
+ else
+ *rfkill = rfkill_alloc(name, &eeepc->platform_device->dev, type,
+ &eeepc_rfkill_ops, (void *)(long)dev_id);
if (!*rfkill)
return -EINVAL;
@@ -636,6 +699,8 @@ static void eeepc_wmi_rfkill_exit(struct eeepc_wmi *eeepc)
eeepc_rfkill_hotplug(eeepc);
if (eeepc->hotplug_slot)
pci_hp_deregister(eeepc->hotplug_slot);
+ if (eeepc->hotplug_workqueue)
+ destroy_workqueue(eeepc->hotplug_workqueue);
if (eeepc->bluetooth_rfkill) {
rfkill_unregister(eeepc->bluetooth_rfkill);
@@ -654,6 +719,7 @@ static int eeepc_wmi_rfkill_init(struct eeepc_wmi *eeepc)
int result = 0;
mutex_init(&eeepc->hotplug_lock);
+ mutex_init(&eeepc->wmi_lock);
result = eeepc_new_rfkill(eeepc, &eeepc->wlan_rfkill,
"eeepc-wlan", RFKILL_TYPE_WLAN,
--
1.7.4.rc3
--
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