• Paul Mackerras's avatar
    [PATCH] ppc32: fix cpu voltage change delay · 15edefdf
    Paul Mackerras authored
    This patch fixes a problem where my new powerbook would sometimes hang or
    crash when changing CPU speed.  We had schedule_timeout(HZ/1000) in there,
    intended to provide a delay of one millisecond.  However, even with
    HZ=1000, it was (I believe) only waiting for the next jiffy before
    proceeding, which could be less than a millisecond.  Changing the code to
    use msleep, and specifying a time of 1 jiffy + 1ms has fixed the problem.
    (When I looked at the msleep code, it appeared to me that msleep(1) with
    HZ=1000 would sleep for between 0 and 1ms.)
    
    Ben also asked me to remove the code that changes the AACK delay enable,
    after looking in the Darwin sources and seeing that Darwin does not change
    this in its corresponding code.
    Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
    Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
    15edefdf
pmac_cpufreq.c 15 KB