On Tue, Nov 28, 2017 at 8:14 AM, Arnd Bergmann <a...@arndb.de> wrote:
> This is a second attempt to allow 64-bit timestamps in packet sockets,
Thanks for coding up this variant.
> The implementation is fairly straightforward, but I'm less sure about the
> interface. Using SOF_TIMESTAMPING_* flags in PACKET_TIMESTAMP is a bit
> odd already since most of the other flags make no sense here. Adding two
> more flags that only make sense for packet sockets but not the normal
> SO_TIMESTAMPING option on other sockets makes this even more confusing.
Agreed.
Unfortunately, we're already stuck with SOL_PACKET/PACKET_TIMESTAMP
accepting SOF_TIMESTAMPING_RAW_HARDWARE.
Perhaps we can define a new PF_PACKET specific enum where the
equivalent option has the same value, so is backwards compatible:
enum {
PACKET_TIMESTAMP_ORIG = 0,
PACKET_TIMESTAMP_ZERO = 1 << 0,
PACKET_TIMESTAMP_NS64 = 1 << 1,
PACKET_TIMESTAMP_HW = 1 << 6
};
and BUILD_BUG_ON(PACKET_TIMESTAMP_RAW != SOF_TIMESTAMPING_RAW_HARDWARE)
to document the dependency.
At high level, the code looks great to me, itself.
