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-rw-r--r--Documentation/networking/packet_mmap.txt18
-rw-r--r--include/uapi/linux/if_packet.h2
-rw-r--r--net/packet/af_packet.c12
3 files changed, 11 insertions, 21 deletions
diff --git a/Documentation/networking/packet_mmap.txt b/Documentation/networking/packet_mmap.txt
index 38112d512f47..a6d7cb91069e 100644
--- a/Documentation/networking/packet_mmap.txt
+++ b/Documentation/networking/packet_mmap.txt
@@ -1008,14 +1008,9 @@ hardware timestamps to be used. Note: you may need to enable the generation
of hardware timestamps with SIOCSHWTSTAMP (see related information from
Documentation/networking/timestamping.txt).
-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;
+PACKET_TIMESTAMP accepts the same integer bit field as SO_TIMESTAMPING:
+
+ int req = SOF_TIMESTAMPING_RAW_HARDWARE;
setsockopt(fd, SOL_PACKET, PACKET_TIMESTAMP, (void *) &req, sizeof(req))
For the mmap(2)ed ring buffers, such timestamps are stored in the
@@ -1023,14 +1018,13 @@ tpacket{,2,3}_hdr structure's tp_sec and tp_{n,u}sec members. To determine
what kind of timestamp has been reported, the tp_status field is binary |'ed
with the following possible bits ...
- TP_STATUS_TS_SYS_HARDWARE
TP_STATUS_TS_RAW_HARDWARE
TP_STATUS_TS_SOFTWARE
... that are equivalent to its SOF_TIMESTAMPING_* counterparts. For the
-RX_RING, if none of those 3 are set (i.e. PACKET_TIMESTAMP is not set),
-then this means that a software fallback was invoked *within* PF_PACKET's
-processing code (less precise).
+RX_RING, if neither is set (i.e. PACKET_TIMESTAMP is not set), then a
+software fallback was invoked *within* PF_PACKET's processing code (less
+precise).
Getting timestamps for the TX_RING works as follows: i) fill the ring frames,
ii) call sendto() e.g. in blocking mode, iii) wait for status of relevant
diff --git a/include/uapi/linux/if_packet.h b/include/uapi/linux/if_packet.h
index bac27fa05f5b..da2d668b8cf1 100644
--- a/include/uapi/linux/if_packet.h
+++ b/include/uapi/linux/if_packet.h
@@ -108,7 +108,7 @@ struct tpacket_auxdata {
/* Rx and Tx ring - header status */
#define TP_STATUS_TS_SOFTWARE (1 << 29)
-#define TP_STATUS_TS_SYS_HARDWARE (1 << 30)
+#define TP_STATUS_TS_SYS_HARDWARE (1 << 30) /* deprecated, never set */
#define TP_STATUS_TS_RAW_HARDWARE (1 << 31)
/* Rx ring - feature request bits */
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 614ca91f785a..8d9f8042705a 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -441,14 +441,10 @@ static __u32 tpacket_get_timestamp(struct sk_buff *skb, struct timespec *ts,
{
struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
- if (shhwtstamps) {
- if ((flags & SOF_TIMESTAMPING_SYS_HARDWARE) &&
- ktime_to_timespec_cond(shhwtstamps->syststamp, ts))
- return TP_STATUS_TS_SYS_HARDWARE;
- if ((flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
- ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts))
- return TP_STATUS_TS_RAW_HARDWARE;
- }
+ if (shhwtstamps &&
+ (flags & SOF_TIMESTAMPING_RAW_HARDWARE) &&
+ ktime_to_timespec_cond(shhwtstamps->hwtstamp, ts))
+ return TP_STATUS_TS_RAW_HARDWARE;
if (ktime_to_timespec_cond(skb->tstamp, ts))
return TP_STATUS_TS_SOFTWARE;

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