• Jean Delvare's avatar
    tools / power: turbostat: Drop temperature checks · 3482124a
    Jean Delvare authored
    The Intel 64 and IA-32 Architectures Software Developer's Manual says
    that TjMax is stored in bits 23:16 of MSR_TEMPERATURE TARGET (0x1a2).
    That's 8 bits, not 7, so it must be masked with 0xFF rather than 0x7F.
    
    The manual has no mention of which values should be considered valid,
    which kind of implies that they all are. Arbitrarily discarding values
    outside a specific range is wrong. The upper range check had to be
    fixed recently (commit 144b44b1) and the lower range check is just as
    wrong. See bug #75071:
    
    https://bugzilla.kernel.org/show_bug.cgi?id=75071
    
    There are many Xeon processor series with TjMax of 70, 71 or 80
    degrees Celsius, way below the arbitrary 85 degrees Celsius limit.
    There may be other (past or future) models with even lower limits.
    
    So drop this arbitrary check. The only value that would be clearly
    invalid is 0. Everything else should be accepted.
    
    After these changes, turbostat is aligned with what the coretemp
    driver does.
    Signed-off-by: default avatarJean Delvare <jdelvare@suse.de>
    Cc: Len Brown <len.brown@intel.com>
    Acked-by: default avatarGuenter Roeck <linux@roeck-us.net>
    Reviewed-by: default avatarJosh Triplett <josh@joshtriplett.org>
    Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
    3482124a
turbostat.c 60.8 KB