[PATCH] libata: Handle bay devices in dock stations

Holger Macht
2008-05-28T14:36:07Z

* Differentiate between bay devices in dock stations and others:

- When an ACPI_NOTIFY_EJECT_REQUEST appears, just signal uevent to
userspace (that is when the optional eject button on a bay device is
pressed/pulled) giving the possibility to unmount file systems and to
clean up. Also, only send uevent in case we get an EJECT_REQUEST
without doing anything else. In other cases, you'll get an add/remove
event because libata attaches/detaches the device.

- In case of a dock event, which in turn signals an
ACPI_NOTIFY_EJECT_REQUEST, immediately detach the device, because it
may already have been gone

* In case of an ACPI_NOTIFY_DEVICE/BUS_CHECK, evaluate _STA to check if
the device has been plugged or unplugged. If plugged, hotplug it, if
unplugged, just signal event to userspace
(initial patch by Matthew Garrett <mjg59@srcf.ucam.org>)

* Call ACPI _EJ0 for detached devices

Signed-off-by: Holger Macht <hmacht@suse.de>
---

Changes regarding the previous patch:

* Make sure kobj does not go away outside locking
* Coding style cleanups
* Call _EJ0 for detached devices

diff --git a/drivers/ata/libata-acpi.c b/drivers/ata/libata-acpi.c
index dbf6ca7..e0e49fd 100644
--- a/drivers/ata/libata-acpi.c
+++ b/drivers/ata/libata-acpi.c
@@ -118,8 +118,40 @@ static void ata_acpi_associate_ide_port(struct ata_port *ap)
ap->pflags |= ATA_PFLAG_INIT_GTM_VALID;
}

+static void ata_acpi_eject_device(acpi_handle handle)
+{
+ struct acpi_object_list arg_list;
+ union acpi_object arg;
+
+ arg_list.count = 1;
+ arg_list.pointer = &arg;
+ arg.type = ACPI_TYPE_INTEGER;
+ arg.integer.value = 1;
+
+ if (ACPI_FAILURE(acpi_evaluate_object(handle, "_EJ0",
+ &arg_list, NULL)))
+ printk(KERN_ERR "Failed to evaluate _EJ0!\n");
+}
+
+static void ata_acpi_detach_device(struct ata_port *ap, struct ata_device *dev)
+{
+ if (dev)
+ dev->flags |= ATA_DFLAG_DETACH;
+ else {
+ struct ata_link *tlink;
+ struct ata_device *tdev;
+
+ ata_port_for_each_link(tlink, ap)
+ ata_link_for_each_dev(tdev, tlink)
+ tdev->flags |= ATA_DFLAG_DETACH;
+ }
+
+ ata_port_freeze(ap);
+ ata_port_schedule_eh(ap);
+}
+
static void ata_acpi_handle_hotplug(struct ata_port *ap, struct ata_device
- *dev, u32 event)
+ *dev, u32 event, int is_dock_event)
{
char event_string[12];
char *envp[] = { event_string, NULL };
@@ -135,83 +167,98 @@ static void ata_acpi_handle_hotplug(struct ata_port *ap, struct ata_device
ap = dev->link->ap;
ehi = &ap->link.eh_info;

- spin_lock_irqsave(ap->lock, flags);
-
- if (dev)
+ if (dev) {
+ if (dev->sdev)
+ kobj = &dev->sdev->sdev_gendev.kobj;
handle = dev->acpi_handle;
- else
+ } else {
+ kobj = &ap->dev->kobj;
handle = ap->acpi_handle;
+ }

status = acpi_get_handle(handle, "_EJ0", &tmphandle);
- if (ACPI_FAILURE(status)) {
- /* This device is not ejectable */
- spin_unlock_irqrestore(ap->lock, flags);
+ if (ACPI_FAILURE(status))
+ /* This device does not support hotplug */
return;
- }

- status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
- if (ACPI_FAILURE(status)) {
- printk ("Unable to determine bay status\n");
- spin_unlock_irqrestore(ap->lock, flags);
- return;
- }
+ spin_lock_irqsave(ap->lock, flags);

switch (event) {
case ACPI_NOTIFY_BUS_CHECK:
case ACPI_NOTIFY_DEVICE_CHECK:
ata_ehi_push_desc(ehi, "ACPI event");
- if (!sta) {
- /* Device has been unplugged */
- if (dev)
- dev->flags |= ATA_DFLAG_DETACH;
- else {
- struct ata_link *tlink;
- struct ata_device *tdev;
-
- ata_port_for_each_link(tlink, ap) {
- ata_link_for_each_dev(tdev, tlink) {
- tdev->flags |=
- ATA_DFLAG_DETACH;
- }
- }
- }
- ata_port_schedule_eh(ap);
- wait = 1;
- } else {
+
+ status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
+ if (ACPI_FAILURE(status)) {
+ printk(KERN_ERR "Unable to determine bay status\n");
+ break;
+ }
+
+ if (sta) {
ata_ehi_hotplugged(ehi);
ata_port_freeze(ap);
+ } else {
+ /* The device has gone - unplug it */
+ ata_acpi_detach_device(ap, dev);
+ wait = 1;
}
- }
+ break;
+ case ACPI_NOTIFY_EJECT_REQUEST:
+ ata_ehi_push_desc(ehi, "ACPI event");

- spin_unlock_irqrestore(ap->lock, flags);
+ if (!is_dock_event)
+ break;

- if (wait)
- ata_port_wait_eh(ap);
+ /* undock event - immediate unplug */
+ ata_acpi_detach_device(ap, dev);
+ wait = 1;
+ break;
+ }

- if (dev) {
- if (dev->sdev)
- kobj = &dev->sdev->sdev_gendev.kobj;
- } else
- kobj = &ap->dev->kobj;
+ /* make sure kobj doesn't go away while ap->lock is released */
+ kobject_get(kobj);
+
+ spin_unlock_irqrestore(ap->lock, flags);

- if (kobj) {
+ if (kobj && !is_dock_event) {
sprintf(event_string, "BAY_EVENT=%d", event);
kobject_uevent_env(kobj, KOBJ_CHANGE, envp);
}
+
+ kobject_put(kobj);
+
+ if (wait) {
+ ata_port_wait_eh(ap);
+ ata_acpi_eject_device(handle);
+ }
+}
+
+static void ata_acpi_dev_notify_dock(acpi_handle handle, u32 event, void *data)
+{
+ struct ata_device *dev = data;
+
+ ata_acpi_handle_hotplug(NULL, dev, event, 1);
+}
+
+static void ata_acpi_ap_notify_dock(acpi_handle handle, u32 event, void *data)
+{
+ struct ata_port *ap = data;
+
+ ata_acpi_handle_hotplug(ap, NULL, event, 1);
}

static void ata_acpi_dev_notify(acpi_handle handle, u32 event, void *data)
{
struct ata_device *dev = data;

- ata_acpi_handle_hotplug(NULL, dev, event);
+ ata_acpi_handle_hotplug(NULL, dev, event, 0);
}

static void ata_acpi_ap_notify(acpi_handle handle, u32 event, void *data)
{
struct ata_port *ap = data;

- ata_acpi_handle_hotplug(ap, NULL, event);
+ ata_acpi_handle_hotplug(ap, NULL, event, 0);
}

/**
@@ -252,7 +299,7 @@ void ata_acpi_associate(struct ata_host *host)
ata_acpi_ap_notify, ap);
/* we might be on a docking station */
register_hotplug_dock_device(ap->acpi_handle,
- ata_acpi_ap_notify, ap);
+ ata_acpi_ap_notify_dock, ap);
}

for (j = 0; j < ata_link_max_devices(&ap->link); j++) {
@@ -264,7 +311,7 @@ void ata_acpi_associate(struct ata_host *host)
ata_acpi_dev_notify, dev);
/* we might be on a docking station */
register_hotplug_dock_device(dev->acpi_handle,
- ata_acpi_dev_notify, dev);
+ ata_acpi_dev_notify_dock, dev);
}
}
}