• Tejun Heo's avatar
    libata: disable LPM for some WD SATA-I devices · f07b772d
    Tejun Heo authored
    commit ecd75ad514d73efc1bbcc5f10a13566c3ace5f53 upstream.
    For some reason, some early WD drives spin up and down drives
    erratically when the link is put into slumber mode which can reduce
    the life expectancy of the device significantly.  Unfortunately, we
    don't have full list of devices and given the nature of the issue it'd
    be better to err on the side of false positives than the other way
    around.  Let's disable LPM on all WD devices which match one of the
    known problematic model prefixes and are SATA-I.
    As horkage list doesn't support matching SATA capabilities, this is
    implemented as two horkages - WD_BROKEN_LPM and NOLPM.  The former is
    set for the known prefixes and sets the latter if the matched device
    is SATA-I.
    Note that this isn't optimal as this disables all LPM operations and
    partial link power state reportedly works fine on these; however, the
    way LPM is implemented in libata makes it difficult to precisely map
    libata LPM setting to specific link power state.  Well, these devices
    are already fairly outdated.  Let's just disable whole LPM for now.
    Signed-off-by: 's avatarTejun Heo <tj@kernel.org>
    Reported-and-tested-by: 's avatarNikos Barkas <levelwol@gmail.com>
    Reported-and-tested-by: 's avatarIoannis Barkas <risc4all@yahoo.com>
    References: https://bugzilla.kernel.org/show_bug.cgi?id=57211Signed-off-by: 's avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
libata-scsi.c 105 KB