Date: Mon, 21 Jun 2010 23:24:35 +0200 (CEST) From: Stefan Richter Subject: 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 --- drivers/firewire/core-card.c | 12 +++++++++--- drivers/firewire/core-cdev.c | 2 +- drivers/firewire/core-topology.c | 1 + include/linux/firewire-cdev.h | 5 +++++ include/linux/firewire.h | 1 + 5 files changed, 17 insertions(+), 4 deletions(-) Index: b/drivers/firewire/core-card.c =================================================================== --- a/drivers/firewire/core-card.c +++ b/drivers/firewire/core-card.c @@ -239,7 +239,7 @@ static void fw_card_bm_work(struct work_ struct fw_card *card = container_of(work, struct fw_card, work.work); struct fw_device *root_device, *irm_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; @@ -315,9 +315,15 @@ static void fw_card_bm_work(struct work_ /* 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); Index: b/drivers/firewire/core-cdev.c =================================================================== --- a/drivers/firewire/core-cdev.c +++ b/drivers/firewire/core-cdev.c @@ -319,7 +319,7 @@ static void fill_bus_reset_event(struct 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; Index: b/drivers/firewire/core-topology.c =================================================================== --- a/drivers/firewire/core-topology.c +++ b/drivers/firewire/core-topology.c @@ -552,6 +552,7 @@ void fw_core_handle_bus_reset(struct fw_ 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); Index: b/include/linux/firewire-cdev.h =================================================================== --- a/include/linux/firewire-cdev.h +++ b/include/linux/firewire-cdev.h @@ -71,6 +71,10 @@ struct fw_cdev_event_common { * 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; @@ -353,6 +357,7 @@ union fw_cdev_event { * 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. */ Index: b/include/linux/firewire.h =================================================================== --- a/include/linux/firewire.h +++ b/include/linux/firewire.h @@ -119,6 +119,7 @@ struct fw_card { int bm_retries; int bm_generation; __be32 bm_transaction_data[2]; + int bm_node_id; bool bm_abdicate; bool priority_budget_implemented; /* controller feature */