#include <linux/device.h>
#include <linux/delay.h>
#include <linux/idr.h>
+#include <linux/jiffies.h>
#include <linux/string.h>
#include <linux/rwsem.h>
#include <linux/semaphore.h>
/*
* Take the card lock so we don't set this to NULL while a
- * FW_NODE_UPDATED callback is being handled.
+ * FW_NODE_UPDATED callback is being handled or while the
+ * bus manager work looks at this node.
*/
spin_lock_irqsave(&card->lock, flags);
device->node->data = NULL;
return device;
}
+/*
+ * These defines control the retry behavior for reading the config
+ * rom. It shouldn't be necessary to tweak these; if the device
+ * doesn't respond to a config rom read within 10 seconds, it's not
+ * going to respond at all. As for the initial delay, a lot of
+ * devices will be able to respond within half a second after bus
+ * reset. On the other hand, it's not really worth being more
+ * aggressive than that, since it scales pretty well; if 10 devices
+ * are plugged in, they're all getting read within one second.
+ */
+
+#define MAX_RETRIES 10
+#define RETRY_DELAY (3 * HZ)
+#define INITIAL_DELAY (HZ / 2)
+#define SHUTDOWN_DELAY (2 * HZ)
+
static void fw_device_shutdown(struct work_struct *work)
{
struct fw_device *device =
container_of(work, struct fw_device, work.work);
int minor = MINOR(device->device.devt);
+ if (time_is_after_jiffies(device->card->reset_jiffies + SHUTDOWN_DELAY)
+ && !list_empty(&device->card->link)) {
+ schedule_delayed_work(&device->work, SHUTDOWN_DELAY);
+ return;
+ }
+
+ if (atomic_cmpxchg(&device->state,
+ FW_DEVICE_GONE,
+ FW_DEVICE_SHUTDOWN) != FW_DEVICE_GONE)
+ return;
+
fw_device_cdev_remove(device);
device_for_each_child(&device->device, NULL, shutdown_unit);
device_unregister(&device->device);
down_write(&fw_device_rwsem);
idr_remove(&fw_device_idr, minor);
up_write(&fw_device_rwsem);
+
fw_device_put(device);
}
.release = fw_device_release,
};
+static void fw_device_update(struct work_struct *work);
+
/*
- * These defines control the retry behavior for reading the config
- * rom. It shouldn't be necessary to tweak these; if the device
- * doesn't respond to a config rom read within 10 seconds, it's not
- * going to respond at all. As for the initial delay, a lot of
- * devices will be able to respond within half a second after bus
- * reset. On the other hand, it's not really worth being more
- * aggressive than that, since it scales pretty well; if 10 devices
- * are plugged in, they're all getting read within one second.
+ * If a device was pending for deletion because its node went away but its
+ * bus info block and root directory header matches that of a newly discovered
+ * device, revive the existing fw_device.
+ * The newly allocated fw_device becomes obsolete instead.
*/
+static int lookup_existing_device(struct device *dev, void *data)
+{
+ struct fw_device *old = fw_device(dev);
+ struct fw_device *new = data;
+ struct fw_card *card = new->card;
+ int match = 0;
+
+ down_read(&fw_device_rwsem); /* serialize config_rom access */
+ spin_lock_irq(&card->lock); /* serialize node access */
+
+ if (memcmp(old->config_rom, new->config_rom, 6 * 4) == 0 &&
+ atomic_cmpxchg(&old->state,
+ FW_DEVICE_GONE,
+ FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
+ struct fw_node *current_node = new->node;
+ struct fw_node *obsolete_node = old->node;
+
+ new->node = obsolete_node;
+ new->node->data = new;
+ old->node = current_node;
+ old->node->data = old;
+
+ old->max_speed = new->max_speed;
+ old->node_id = current_node->node_id;
+ smp_wmb(); /* update node_id before generation */
+ old->generation = card->generation;
+ old->config_rom_retries = 0;
+ fw_notify("rediscovered device %s\n", dev_name(dev));
-#define MAX_RETRIES 10
-#define RETRY_DELAY (3 * HZ)
-#define INITIAL_DELAY (HZ / 2)
+ PREPARE_DELAYED_WORK(&old->work, fw_device_update);
+ schedule_delayed_work(&old->work, 0);
+
+ if (current_node == card->root_node)
+ fw_schedule_bm_work(card, 0);
+
+ match = 1;
+ }
+
+ spin_unlock_irq(&card->lock);
+ up_read(&fw_device_rwsem);
+
+ return match;
+}
static void fw_device_init(struct work_struct *work)
{
struct fw_device *device =
container_of(work, struct fw_device, work.work);
+ struct device *revived_dev;
int minor, err;
/*
return;
}
- err = -ENOMEM;
+ revived_dev = device_find_child(device->card->device,
+ device, lookup_existing_device);
+ if (revived_dev) {
+ put_device(revived_dev);
+ fw_device_release(&device->device);
+
+ return;
+ }
+
+ device_initialize(&device->device);
fw_device_get(device);
down_write(&fw_device_rwsem);
- if (idr_pre_get(&fw_device_idr, GFP_KERNEL))
- err = idr_get_new(&fw_device_idr, device, &minor);
+ err = idr_pre_get(&fw_device_idr, GFP_KERNEL) ?
+ idr_get_new(&fw_device_idr, device, &minor) :
+ -ENOMEM;
up_write(&fw_device_rwsem);
if (err < 0)
* fw_node_event().
*/
if (atomic_cmpxchg(&device->state,
- FW_DEVICE_INITIALIZING,
- FW_DEVICE_RUNNING) == FW_DEVICE_SHUTDOWN) {
- fw_device_shutdown(work);
+ FW_DEVICE_INITIALIZING,
+ FW_DEVICE_RUNNING) == FW_DEVICE_GONE) {
+ PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
+ schedule_delayed_work(&device->work, SHUTDOWN_DELAY);
} else {
if (device->config_rom_retries)
fw_notify("created device %s: GUID %08x%08x, S%d00, "
case REREAD_BIB_UNCHANGED:
if (atomic_cmpxchg(&device->state,
- FW_DEVICE_INITIALIZING,
- FW_DEVICE_RUNNING) == FW_DEVICE_SHUTDOWN)
+ FW_DEVICE_INITIALIZING,
+ FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
goto gone;
fw_device_update(work);
create_units(device);
if (atomic_cmpxchg(&device->state,
- FW_DEVICE_INITIALIZING,
- FW_DEVICE_RUNNING) == FW_DEVICE_SHUTDOWN)
+ FW_DEVICE_INITIALIZING,
+ FW_DEVICE_RUNNING) == FW_DEVICE_GONE)
goto gone;
fw_notify("refreshed device %s\n", dev_name(&device->device));
give_up:
fw_notify("giving up on refresh of device %s\n", dev_name(&device->device));
gone:
- atomic_set(&device->state, FW_DEVICE_SHUTDOWN);
- fw_device_shutdown(work);
+ atomic_set(&device->state, FW_DEVICE_GONE);
+ PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
+ schedule_delayed_work(&device->work, SHUTDOWN_DELAY);
out:
if (node_id == card->root_node->node_id)
fw_schedule_bm_work(card, 0);
/*
* Do minimal intialization of the device here, the
- * rest will happen in fw_device_init(). We need the
- * card and node so we can read the config rom and we
- * need to do device_initialize() now so
- * device_for_each_child() in FW_NODE_UPDATED is
- * doesn't freak out.
+ * rest will happen in fw_device_init().
+ *
+ * Attention: A lot of things, even fw_device_get(),
+ * cannot be done before fw_device_init() finished!
+ * You can basically just check device->state and
+ * schedule work until then, but only while holding
+ * card->lock.
*/
- device_initialize(&device->device);
atomic_set(&device->state, FW_DEVICE_INITIALIZING);
device->card = fw_card_get(card);
device->node = fw_node_get(node);
*/
device = node->data;
if (atomic_xchg(&device->state,
- FW_DEVICE_SHUTDOWN) == FW_DEVICE_RUNNING) {
+ FW_DEVICE_GONE) == FW_DEVICE_RUNNING) {
PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
- schedule_delayed_work(&device->work, 0);
+ schedule_delayed_work(&device->work,
+ list_empty(&card->link) ? 0 : SHUTDOWN_DELAY);
}
break;
}
projects / linux-2.6-omap-h63xx.git / blobdiff