• Matthew Garrett's avatar
    [CPUFREQ] pcc driver should check for pcch method before calling _OSC · 47f8bcf3
    Matthew Garrett authored
    The pcc specification documents an _OSC method that's incompatible with the
    one defined as part of the ACPI spec. This shouldn't be a problem as both
    are supposed to be guarded with a UUID. Unfortunately approximately nobody
    (including HP, who wrote this spec) properly check the UUID on entry to the
    _OSC call. Right now this could result in surprising behaviour if the pcc
    driver performs an _OSC call on a machine that doesn't implement the pcc
    specification. Check whether the PCCH method exists first in order to reduce
    this probability.
    Signed-off-by: default avatarMatthew Garrett <mjg@redhat.com>
    Cc: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
    Signed-off-by: default avatarDave Jones <davej@redhat.com>
pcc-cpufreq.c 15.5 KB