cvs commit: src/sys/dev/mc146818 mc146818.c src/sys/kern subr_witness.c src/sys/sparc64/sparc64 rtc.c

[Marius Strobl]

marius      2005-06-04 23:24:50 UTC

  FreeBSD src repository

  Modified files:
    sys/dev/mc146818     mc146818.c 
    sys/kern             subr_witness.c 
    sys/sparc64/sparc64  rtc.c 
  Log:
  After some input from bde@ and rereading the datasheet use a MTX_SPIN
  mutex instead of a MTX_DEF one in order to defer preemption while
  reading the date and time registers. If we don't manage to read them
  within the time slot where we are guaranteed that no updates occur we
  might actually read them during an update in which case the output is
  undefined.
  
  Revision  Changes    Path
  1.4       +11 -11    src/sys/dev/mc146818/mc146818.c
  1.195     +1 -0      src/sys/kern/subr_witness.c
  1.4       +1 -1      src/sys/sparc64/sparc64/rtc.c