diff options
Diffstat (limited to 'drivers/firewire')
| -rw-r--r-- | drivers/firewire/core-device.c | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/drivers/firewire/core-device.c b/drivers/firewire/core-device.c index d6e54a5173fc..97e656af2d22 100644 --- a/drivers/firewire/core-device.c +++ b/drivers/firewire/core-device.c @@ -580,7 +580,9 @@ static int read_bus_info_block(struct fw_device *device, int generation) kfree(old_rom); ret = 0; - device->cmc = rom[2] >> 30 & 1; + device->max_rec = rom[2] >> 12 & 0xf; + device->cmc = rom[2] >> 30 & 1; + device->irmc = rom[2] >> 31 & 1; out: kfree(rom); @@ -841,6 +843,20 @@ static void set_broadcast_channel(struct fw_device *device, int generation) if (!card->broadcast_channel_allocated) return; + /* + * The Broadcast_Channel Valid bit is required by nodes which want to + * transmit on this channel. Such transmissions are practically + * exclusive to IP over 1394 (RFC 2734). IP capable nodes are required + * to be IRM capable and have a max_rec of 8 or more. We use this fact + * to narrow down to which nodes we send Broadcast_Channel updates. + */ + if (!device->irmc || device->max_rec < 8) + return; + + /* + * Some 1394-1995 nodes crash if this 1394a-2000 register is written. + * Perform a read test first. + */ if (device->bc_implemented == BC_UNKNOWN) { rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST, device->node_id, generation, device->max_speed, |