• Hans de Goede's avatar
    uas: Disable uas on ASM1051 devices · a9c54caa
    Hans de Goede authored
    There are a large numbers of issues with ASM1051 devices in uas mode:
    
    1) They do not support REPORT SUPPORTED OPERATION CODES
    
    2) They use out of spec 8 byte status iu-s when they have no sense data,
       switching to normal 16 byte status iu-s when they do have sense data.
    
    3) They hang / crash when combined with some disks, e.g. a Crucial M500 ssd.
    
    4) They hang / crash when stressed (through e.g. sg_reset --bus) with disks
       with which then normally do work (once 1 & 2 are worked around).
    
    Where as in BOT mode they appear to work fine, so the best way forward with
    these devices is to just blacklist them for uas usage.
    
    Unfortunately this is easier said then done. as older versions of the ASM1053
    (which works fine) use the same usb-id as the ASM1051.
    
    When connected over USB-3 the 2 can be told apart by the number of streams
    they support. So this patch adds some less then pretty code to disable uas for
    the ASM1051. When connected over USB-2, simply disable uas alltogether for
    devices with the shared usb-id.
    
    Cc: stable@vger.kernel.org # 3.16
    Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    a9c54caa
uas-detect.h 2.92 KB