firewire: cdev: add PHY pinging
This extends the FW_CDEV_IOC_SEND_PHY_PACKET ioctl() for /dev/fw* to be
useful for ping time measurements. One application for it would be gap
count optimization in userspace that is based on ping times rather than
hop count. (The latter is implemented in firewire-core itself but is
not applicable to beta PHYs that act as repeater.)
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c
index 0425dd5..31863cf 100644
--- a/drivers/firewire/core-cdev.c
+++ b/drivers/firewire/core-cdev.c
@@ -1423,9 +1423,10 @@
/* stale generation; cancelled; on certain controllers: no ack */
default: e->phy_packet.rcode = status; break;
}
+ e->phy_packet.data[0] = packet->timestamp;
- queue_event(e->client, &e->event,
- &e->phy_packet, sizeof(e->phy_packet), NULL, 0);
+ queue_event(e->client, &e->event, &e->phy_packet,
+ sizeof(e->phy_packet) + e->phy_packet.length, NULL, 0);
client_put(e->client);
}
@@ -1439,7 +1440,7 @@
if (!client->device->is_local)
return -ENOSYS;
- e = kzalloc(sizeof(*e), GFP_KERNEL);
+ e = kzalloc(sizeof(*e) + 4, GFP_KERNEL);
if (e == NULL)
return -ENOMEM;
@@ -1453,6 +1454,8 @@
e->p.callback = outbound_phy_packet_callback;
e->phy_packet.closure = a->closure;
e->phy_packet.type = FW_CDEV_EVENT_PHY_PACKET_SENT;
+ if (is_ping_packet(a->data))
+ e->phy_packet.length = 4;
card->driver->send_request(card, &e->p);
diff --git a/drivers/firewire/core.h b/drivers/firewire/core.h
index 3102b6b..28621e4 100644
--- a/drivers/firewire/core.h
+++ b/drivers/firewire/core.h
@@ -234,4 +234,9 @@
void fw_send_phy_config(struct fw_card *card,
int node_id, int generation, int gap_count);
+static inline bool is_ping_packet(u32 *data)
+{
+ return (data[0] & 0xc0ffffff) == 0 && ~data[0] == data[1];
+}
+
#endif /* _FIREWIRE_CORE_H */
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 08afccc..5f6bb2c 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -1068,6 +1068,9 @@
header[1] = cpu_to_le32(packet->header[0]);
header[2] = cpu_to_le32(packet->header[1]);
d[0].req_count = cpu_to_le16(12);
+
+ if (is_ping_packet(packet->header))
+ d[0].control |= cpu_to_le16(DESCRIPTOR_PING);
break;
case 4: