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authorLinus Torvalds <torvalds@linux-foundation.org>2010-08-04 11:47:58 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-08-04 11:47:58 -0700
commit6ba74014c1ab0e37af7de6f64b4eccbbae3cb9e7 (patch)
tree8f3892fc44f1e403675a6d7e88fda5c70e56ee4c /Documentation/networking/packet_mmap.txt
parent5abd9ccced7a726c817dd6b5b96bc933859138d1 (diff)
parent3ff1c25927e3af61c6bf0e4ed959504058ae4565 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1443 commits) phy/marvell: add 88ec048 support igb: Program MDICNFG register prior to PHY init e1000e: correct MAC-PHY interconnect register offset for 82579 hso: Add new product ID can: Add driver for esd CAN-USB/2 device l2tp: fix export of header file for userspace can-raw: Fix skb_orphan_try handling Revert "net: remove zap_completion_queue" net: cleanup inclusion phy/marvell: add 88e1121 interface mode support u32: negative offset fix net: Fix a typo from "dev" to "ndev" igb: Use irq_synchronize per vector when using MSI-X ixgbevf: fix null pointer dereference due to filter being set for VLAN 0 e1000e: Fix irq_synchronize in MSI-X case e1000e: register pm_qos request on hardware activation ip_fragment: fix subtracting PPPOE_SES_HLEN from mtu twice net: Add getsockopt support for TCP thin-streams cxgb4: update driver version cxgb4: add new PCI IDs ... Manually fix up conflicts in: - drivers/net/e1000e/netdev.c: due to pm_qos registration infrastructure changes - drivers/net/phy/marvell.c: conflict between adding 88ec048 support and cleaning up the IDs - drivers/net/wireless/ipw2x00/ipw2100.c: trivial ipw2100_pm_qos_req conflict (registration change vs marking it static)
Diffstat (limited to 'Documentation/networking/packet_mmap.txt')
-rw-r--r--Documentation/networking/packet_mmap.txt26
1 files changed, 26 insertions, 0 deletions
diff --git a/Documentation/networking/packet_mmap.txt b/Documentation/networking/packet_mmap.txt
index 98f71a5cef0..2546aa4dc23 100644
--- a/Documentation/networking/packet_mmap.txt
+++ b/Documentation/networking/packet_mmap.txt
@@ -493,6 +493,32 @@ The user can also use poll() to check if a buffer is available:
pfd.events = POLLOUT;
retval = poll(&pfd, 1, timeout);
+-------------------------------------------------------------------------------
++ PACKET_TIMESTAMP
+-------------------------------------------------------------------------------
+
+The PACKET_TIMESTAMP setting determines the source of the timestamp in
+the packet meta information. If your NIC is capable of timestamping
+packets in hardware, you can request those hardware timestamps to used.
+Note: you may need to enable the generation of hardware timestamps with
+SIOCSHWTSTAMP.
+
+PACKET_TIMESTAMP accepts the same integer bit field as
+SO_TIMESTAMPING. However, only the SOF_TIMESTAMPING_SYS_HARDWARE
+and SOF_TIMESTAMPING_RAW_HARDWARE values are recognized by
+PACKET_TIMESTAMP. SOF_TIMESTAMPING_SYS_HARDWARE takes precedence over
+SOF_TIMESTAMPING_RAW_HARDWARE if both bits are set.
+
+ int req = 0;
+ req |= SOF_TIMESTAMPING_SYS_HARDWARE;
+ setsockopt(fd, SOL_PACKET, PACKET_TIMESTAMP, (void *) &req, sizeof(req))
+
+If PACKET_TIMESTAMP is not set, a software timestamp generated inside
+the networking stack is used (the behavior before this setting was added).
+
+See include/linux/net_tstamp.h and Documentation/networking/timestamping
+for more information on hardware timestamps.
+
--------------------------------------------------------------------------------
+ THANKS
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