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| author | Gerhard Engleder <gerhard@engleder-embedded.com> | 2022-05-06 22:01:38 +0200 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2022-05-10 09:48:08 +0200 |
| commit | 51eb7492af276b5b4d27cfa4474d40bdac7b9cf8 (patch) | |
| tree | e0fff209136de8a5af800b4486a659f9bacb3b73 | |
| parent | 42704b26b0f1d891f6cf4ebc877dbac0d17c690d (diff) | |
| download | lwn-51eb7492af276b5b4d27cfa4474d40bdac7b9cf8.tar.gz lwn-51eb7492af276b5b4d27cfa4474d40bdac7b9cf8.zip | |
ptp: Request cycles for TX timestamp
The free running cycle counter of physical clocks called cycles shall be
used for hardware timestamps to enable synchronisation.
Introduce new flag SKBTX_HW_TSTAMP_USE_CYCLES, which signals driver to
provide a TX timestamp based on cycles if cycles are supported.
Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
| -rw-r--r-- | include/linux/skbuff.h | 7 | ||||
| -rw-r--r-- | net/socket.c | 11 |
2 files changed, 16 insertions, 2 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index d58669d6cb91..4a4f25975ca2 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -615,6 +615,9 @@ enum { /* device driver is going to provide hardware time stamp */ SKBTX_IN_PROGRESS = 1 << 2, + /* generate hardware time stamp based on cycles if supported */ + SKBTX_HW_TSTAMP_USE_CYCLES = 1 << 3, + /* generate wifi status information (where possible) */ SKBTX_WIFI_STATUS = 1 << 4, @@ -624,7 +627,9 @@ enum { #define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \ SKBTX_SCHED_TSTAMP) -#define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP) +#define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | \ + SKBTX_HW_TSTAMP_USE_CYCLES | \ + SKBTX_ANY_SW_TSTAMP) /* Definitions for flags in struct skb_shared_info */ enum { diff --git a/net/socket.c b/net/socket.c index f0c39c874665..5c1c5e6100e1 100644 --- a/net/socket.c +++ b/net/socket.c @@ -683,9 +683,18 @@ void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags) { u8 flags = *tx_flags; - if (tsflags & SOF_TIMESTAMPING_TX_HARDWARE) + if (tsflags & SOF_TIMESTAMPING_TX_HARDWARE) { flags |= SKBTX_HW_TSTAMP; + /* PTP hardware clocks can provide a free running cycle counter + * as a time base for virtual clocks. Tell driver to use the + * free running cycle counter for timestamp if socket is bound + * to virtual clock. + */ + if (tsflags & SOF_TIMESTAMPING_BIND_PHC) + flags |= SKBTX_HW_TSTAMP_USE_CYCLES; + } + if (tsflags & SOF_TIMESTAMPING_TX_SOFTWARE) flags |= SKBTX_SW_TSTAMP; |