• Arnd Bergmann's avatar
    ALSA: seq_timer: use monotonic times internally · 3915bf29
    Arnd Bergmann authored
    The sequencer client manager reports timestamps in units of unsigned
    32-bit seconds/nanoseconds, but that does not suffer from the y2038
    overflow because it stores only the delta since the 'last_update'
    time was recorded.
    However, the use of the do_gettimeofday() function is problematic
    and we have to replace it to avoid the overflow on on 32-bit
    This uses 'struct timespec64' to record 'last_update', and changes
    the code to use monotonic timestamps that do not suffer from leap
    seconds and settimeofday updates.
    As a side-effect, the code can now use the timespec64_sub() helper
    and become more readable and also avoid a multiplication to convert
    from microseconds to nanoseconds.
    Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
    Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
seq_timer.h 4.65 KB