Per this conversation https://lkml.org/lkml/2012/11/27/587 limit the maximum transmission to the IEEE 1394-2008 specification maximum size of 4096 bytes for asynchronous packets.
Signed-off-by: Peter Hurley <[email protected]> --- drivers/staging/fwserial/TODO | 3 --- drivers/staging/fwserial/fwserial.c | 8 ++++---- drivers/staging/fwserial/fwserial.h | 4 ++-- 3 files changed, 6 insertions(+), 9 deletions(-) diff --git a/drivers/staging/fwserial/TODO b/drivers/staging/fwserial/TODO index 7269005..ffe47d1 100644 --- a/drivers/staging/fwserial/TODO +++ b/drivers/staging/fwserial/TODO @@ -12,9 +12,6 @@ TODOs 1. This driver uses the same unregistered vendor id that the firewire core does (0xd00d1e). Perhaps this could be exposed as a define in firewire-constants.h? -2. MAX_ASYNC_PAYLOAD needs to be publicly exposed by core/ohci - - otherwise how will this driver know the max size of address window to - open for one packet write? 3. Maybe device_max_receive() and link_speed_to_max_payload() should be taken up by the firewire core? 4. To avoid dropping rx data while still limiting the maximum buffering, diff --git a/drivers/staging/fwserial/fwserial.c b/drivers/staging/fwserial/fwserial.c index be5db8a..db1378d 100644 --- a/drivers/staging/fwserial/fwserial.c +++ b/drivers/staging/fwserial/fwserial.c @@ -174,10 +174,11 @@ static void dump_profile(struct seq_file *m, struct stats *stats) #define dump_profile(m, stats) #endif -/* Returns the max receive packet size for the given card */ +/* Returns the max receive packet size for the given node */ static inline int device_max_receive(struct fw_device *fw_device) { - return 1 << (clamp_t(int, fw_device->max_rec, 8U, 13U) + 1); + /* see IEEE 1394-2008 table 8-8 */ + return 1 << (clamp_t(int, fw_device->max_rec, 8U, 11U) + 1); } static void fwtty_log_tx_error(struct fwtty_port *port, int rcode) @@ -1683,8 +1684,7 @@ static void fwserial_virt_plug_complete(struct fwtty_peer *peer, /* reconfigure tx_fifo optimally for this peer */ spin_lock_bh(&port->lock); - port->max_payload = min3(peer->max_payload, peer->fifo_len, - MAX_ASYNC_PAYLOAD); + port->max_payload = min(peer->max_payload, peer->fifo_len); dma_fifo_change_tx_limit(&port->tx_fifo, port->max_payload); spin_unlock_bh(&peer->port->lock); diff --git a/drivers/staging/fwserial/fwserial.h b/drivers/staging/fwserial/fwserial.h index cb0eea0..953ece6 100644 --- a/drivers/staging/fwserial/fwserial.h +++ b/drivers/staging/fwserial/fwserial.h @@ -377,8 +377,8 @@ static inline void fwtty_bind_console(struct fwtty_port *port, */ static inline int link_speed_to_max_payload(unsigned speed) { - speed = clamp(speed, (unsigned) SCODE_100, (unsigned) SCODE_3200); - return 1 << (speed + 9); + /* Max async payload is 4096 - see IEEE 1394-2008 tables 6-4, 16-18 */ + return min(512 << speed, 4096); } #endif /* _FIREWIRE_FWSERIAL_H */ -- 1.8.0.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
