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Iso reception: Use packet timestamps in juju ABI v2 

In the firewire-cdev ABI v1, the kernel exported only the timestamp
of interrupt packets.  libraw1394 estimated the cycle of all packets
between interrupt packets by continuously incrementing the cycle.

In v2 of the ABI, we can obtain an accurate timestamp of each packet
as provided by the OHCI controller.  AFAIU, this is also what you got
from raw1394/ ohci1394.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
This commit is contained in:
Stefan Richter 2009-01-11 22:46:48 +01:00
parent c58e16442b
commit 49dda1ef90
1 changed files with 13 additions and 3 deletions
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16
src/fw-iso.c
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@ -141,12 +141,17 @@ int fw_iso_xmit_start(raw1394handle_t handle, int start_on_cycle,
return 0; return 0;
} }
static inline int recv_header_length(fw_handle_t handle)
{
return handle->abi_version >= 2 ? 8 : 4;
}
static int static int
queue_recv_packets(fw_handle_t handle) queue_recv_packets(fw_handle_t handle)
{ {
while (handle->iso.packet_count <= handle->iso.buf_packets) while (handle->iso.packet_count <= handle->iso.buf_packets)
queue_packet(handle, handle->iso.max_packet_size, 4, 0, 0); queue_packet(handle, handle->iso.max_packet_size,
recv_header_length(handle), 0, 0);
return 0; return 0;
} }
@ -159,9 +164,11 @@ flush_recv_packets(raw1394handle_t handle,
quadlet_t header, *p, *end; quadlet_t header, *p, *end;
unsigned int len, cycle, dropped; unsigned int len, cycle, dropped;
unsigned char channel, tag, sy; unsigned char channel, tag, sy;
int header_has_timestamp;
p = interrupt->header; p = interrupt->header;
end = (void *) interrupt->header + interrupt->header_length; end = (void *) interrupt->header + interrupt->header_length;
header_has_timestamp = fwhandle->abi_version >= 2;
cycle = interrupt->cycle; cycle = interrupt->cycle;
dropped = 0; dropped = 0;
d = RAW1394_ISO_OK; d = RAW1394_ISO_OK;
@ -173,6 +180,9 @@ flush_recv_packets(raw1394handle_t handle,
channel = (header >> 8) & 0x3f; channel = (header >> 8) & 0x3f;
sy = header & 0x0f; sy = header & 0x0f;
if (header_has_timestamp)
cycle = be32_to_cpu(*p++) & 0x1fff;
d = fwhandle->iso.recv_handler(handle, fwhandle->iso.tail, len, d = fwhandle->iso.recv_handler(handle, fwhandle->iso.tail, len,
channel, tag, sy, cycle, dropped); channel, tag, sy, cycle, dropped);
if (d != RAW1394_ISO_OK) if (d != RAW1394_ISO_OK)
@ -420,7 +430,7 @@ iso_init(fw_handle_t handle, int type,
create.type = type; create.type = type;
create.channel = channel; create.channel = channel;
create.speed = speed; create.speed = speed;
create.header_size = 4; create.header_size = recv_header_length(handle);
retval = ioctl(handle->iso.fd, retval = ioctl(handle->iso.fd,
FW_CDEV_IOC_CREATE_ISO_CONTEXT, &create); FW_CDEV_IOC_CREATE_ISO_CONTEXT, &create);