firewire: cdev: fix fw_cdev_event_bus_reset.bm_node_id
Fix an obscure ABI feature that is a bit of a hassle to implement.
However, somebody put it into the ABI, so let's fill in a sensible
value there.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/core-card.c b/drivers/firewire/core-card.c
index 11fc815..6c316cf 100644
--- a/drivers/firewire/core-card.c
+++ b/drivers/firewire/core-card.c
@@ -239,7 +239,7 @@
struct fw_card *card = container_of(work, struct fw_card, work.work);
struct fw_device *root_device;
struct fw_node *root_node;
- int root_id, new_root_id, irm_id, local_id;
+ int root_id, new_root_id, irm_id, bm_id, local_id;
int gap_count, generation, grace, rcode;
bool do_reset = false;
bool root_device_is_running;
@@ -301,9 +301,15 @@
/* Another bus reset, BM work has been rescheduled. */
goto out;
- if (rcode == RCODE_COMPLETE &&
- card->bm_transaction_data[0] != cpu_to_be32(0x3f)) {
+ bm_id = be32_to_cpu(card->bm_transaction_data[0]);
+ spin_lock_irq(&card->lock);
+ if (rcode == RCODE_COMPLETE && generation == card->generation)
+ card->bm_node_id =
+ bm_id == 0x3f ? local_id : 0xffc0 | bm_id;
+ spin_unlock_irq(&card->lock);
+
+ if (rcode == RCODE_COMPLETE && bm_id != 0x3f) {
/* Somebody else is BM. Only act as IRM. */
if (local_id == irm_id)
allocate_broadcast_channel(card, generation);
diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c
index 9b8df20..d8ac0ce 100644
--- a/drivers/firewire/core-cdev.c
+++ b/drivers/firewire/core-cdev.c
@@ -318,7 +318,7 @@
event->generation = client->device->generation;
event->node_id = client->device->node_id;
event->local_node_id = card->local_node->node_id;
- event->bm_node_id = 0; /* FIXME: We don't track the BM. */
+ event->bm_node_id = card->bm_node_id;
event->irm_node_id = card->irm_node->node_id;
event->root_node_id = card->root_node->node_id;
diff --git a/drivers/firewire/core-topology.c b/drivers/firewire/core-topology.c
index 56e908b..88d5133 100644
--- a/drivers/firewire/core-topology.c
+++ b/drivers/firewire/core-topology.c
@@ -552,6 +552,7 @@
smp_wmb();
card->generation = generation;
card->reset_jiffies = jiffies;
+ card->bm_node_id = 0xffff;
card->bm_abdicate = bm_abdicate;
fw_schedule_bm_work(card, 0);
diff --git a/include/linux/firewire-cdev.h b/include/linux/firewire-cdev.h
index 8b9b273..d31022b 100644
--- a/include/linux/firewire-cdev.h
+++ b/include/linux/firewire-cdev.h
@@ -66,6 +66,10 @@
* This event is sent when the bus the device belongs to goes through a bus
* reset. It provides information about the new bus configuration, such as
* new node ID for this device, new root ID, and others.
+ *
+ * If @bm_node_id is 0xffff right after bus reset it can be reread by an
+ * %FW_CDEV_IOC_GET_INFO ioctl after bus manager selection was finished.
+ * Kernels with ABI version < 4 do not set @bm_node_id.
*/
struct fw_cdev_event_bus_reset {
__u64 closure;
@@ -348,6 +352,7 @@
* 3 (2.6.34) - made &fw_cdev_get_cycle_timer reliable
* - added %FW_CDEV_IOC_GET_CYCLE_TIMER2
* 4 (2.6.36) - added %FW_CDEV_EVENT_REQUEST2
+ * - implemented &fw_cdev_event_bus_reset.bm_node_id
*/
#define FW_CDEV_VERSION 3 /* Meaningless; don't use this macro. */
diff --git a/include/linux/firewire.h b/include/linux/firewire.h
index e44b502..db30a75 100644
--- a/include/linux/firewire.h
+++ b/include/linux/firewire.h
@@ -119,6 +119,7 @@
int bm_retries;
int bm_generation;
__be32 bm_transaction_data[2];
+ int bm_node_id;
bool bm_abdicate;
bool priority_budget_implemented; /* controller feature */