[PATCH v2 3/6] staging/fwserial: Limit tx/rx to 1394-2008 spec maximum
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
---
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(>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(>tx_fifo, port->max_payload);
spin_unlock_bh(>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 majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[PATCH v2 3/6] staging/fwserial: Limit tx/rx to 1394-2008 spec maximum
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 pe...@hurleysoftware.com
---
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 majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
