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authorDavid S. Miller <davem@davemloft.net>2014-03-14 22:31:55 -0400
committerDavid S. Miller <davem@davemloft.net>2014-03-14 22:31:55 -0400
commit85dcce7a73f1cc59f7a96fe52713b1630f4ca272 (patch)
tree6c645923eb2f0152073b90685ce80e46cfb7afed /Documentation/networking
parent4c4e4113db249c828fffb286bc95ffb255e081f5 (diff)
parenta4ecdf82f8ea49f7d3a072121dcbd0bf3a7cb93a (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts: drivers/net/usb/r8152.c drivers/net/xen-netback/netback.c Both the r8152 and netback conflicts were simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation/networking')
-rw-r--r--Documentation/networking/packet_mmap.txt2
-rw-r--r--Documentation/networking/timestamping.txt52
2 files changed, 33 insertions, 21 deletions
diff --git a/Documentation/networking/packet_mmap.txt b/Documentation/networking/packet_mmap.txt
index 1404674c0a02..6fea79efb4cb 100644
--- a/Documentation/networking/packet_mmap.txt
+++ b/Documentation/networking/packet_mmap.txt
@@ -453,7 +453,7 @@ TP_STATUS_COPY : This flag indicates that the frame (and associated
453 enabled previously with setsockopt() and 453 enabled previously with setsockopt() and
454 the PACKET_COPY_THRESH option. 454 the PACKET_COPY_THRESH option.
455 455
456 The number of frames than can be buffered to 456 The number of frames that can be buffered to
457 be read with recvfrom is limited like a normal socket. 457 be read with recvfrom is limited like a normal socket.
458 See the SO_RCVBUF option in the socket (7) man page. 458 See the SO_RCVBUF option in the socket (7) man page.
459 459
diff --git a/Documentation/networking/timestamping.txt b/Documentation/networking/timestamping.txt
index 661d3c316a17..048c92b487f6 100644
--- a/Documentation/networking/timestamping.txt
+++ b/Documentation/networking/timestamping.txt
@@ -21,26 +21,38 @@ has such a feature).
21 21
22SO_TIMESTAMPING: 22SO_TIMESTAMPING:
23 23
24Instructs the socket layer which kind of information is wanted. The 24Instructs the socket layer which kind of information should be collected
25parameter is an integer with some of the following bits set. Setting 25and/or reported. The parameter is an integer with some of the following
26other bits is an error and doesn't change the current state. 26bits set. Setting other bits is an error and doesn't change the current
27 27state.
28SOF_TIMESTAMPING_TX_HARDWARE: try to obtain send time stamp in hardware 28
29SOF_TIMESTAMPING_TX_SOFTWARE: if SOF_TIMESTAMPING_TX_HARDWARE is off or 29Four of the bits are requests to the stack to try to generate
30 fails, then do it in software 30timestamps. Any combination of them is valid.
31SOF_TIMESTAMPING_RX_HARDWARE: return the original, unmodified time stamp 31
32 as generated by the hardware 32SOF_TIMESTAMPING_TX_HARDWARE: try to obtain send time stamps in hardware
33SOF_TIMESTAMPING_RX_SOFTWARE: if SOF_TIMESTAMPING_RX_HARDWARE is off or 33SOF_TIMESTAMPING_TX_SOFTWARE: try to obtain send time stamps in software
34 fails, then do it in software 34SOF_TIMESTAMPING_RX_HARDWARE: try to obtain receive time stamps in hardware
35SOF_TIMESTAMPING_RAW_HARDWARE: return original raw hardware time stamp 35SOF_TIMESTAMPING_RX_SOFTWARE: try to obtain receive time stamps in software
36SOF_TIMESTAMPING_SYS_HARDWARE: return hardware time stamp transformed to 36
37 the system time base 37The other three bits control which timestamps will be reported in a
38SOF_TIMESTAMPING_SOFTWARE: return system time stamp generated in 38generated control message. If none of these bits are set or if none of
39 software 39the set bits correspond to data that is available, then the control
40 40message will not be generated:
41SOF_TIMESTAMPING_TX/RX determine how time stamps are generated. 41
42SOF_TIMESTAMPING_RAW/SYS determine how they are reported in the 42SOF_TIMESTAMPING_SOFTWARE: report systime if available
43following control message: 43SOF_TIMESTAMPING_SYS_HARDWARE: report hwtimetrans if available
44SOF_TIMESTAMPING_RAW_HARDWARE: report hwtimeraw if available
45
46It is worth noting that timestamps may be collected for reasons other
47than being requested by a particular socket with
48SOF_TIMESTAMPING_[TR]X_(HARD|SOFT)WARE. For example, most drivers that
49can generate hardware receive timestamps ignore
50SOF_TIMESTAMPING_RX_HARDWARE. It is still a good idea to set that flag
51in case future drivers pay attention.
52
53If timestamps are reported, they will appear in a control message with
54cmsg_level==SOL_SOCKET, cmsg_type==SO_TIMESTAMPING, and a payload like
55this:
44 56
45struct scm_timestamping { 57struct scm_timestamping {
46 struct timespec systime; 58 struct timespec systime;