• Sui Chen's avatar
    ahci: Acer SA5-271 SSD Not Detected Fix · d9f48c46
    Sui Chen authored
    commit 8bfd1743 upstream.
    
    (Correction in this resend: fixed function name acer_sa5_271_workaround; fixed
     the always-true condition in the function; fixed description.)
    
    On the Acer Switch Alpha 12 (model number: SA5-271), the internal SSD may not
    get detected because the port_map and CAP.nr_ports combination causes the driver
    to skip the port that is actually connected to the SSD. More specifically,
    either all SATA ports are identified as DUMMY, or all ports get ``link down''
    and never get up again.
    
    This problem occurs occasionally. When this problem occurs, CAP may hold a
    value of 0xC734FF00 or 0xC734FF01 and port_map may hold a value of 0x00 or 0x01.
    When this problem does not occur, CAP holds a value of 0xC734FF02 and port_map
    may hold a value of 0x07. Overriding the CAP value to 0xC734FF02 and port_map to
    0x7 significantly reduces the occurrence of this problem.
    
    Link: https://bugzilla.kernel.org/attachment.cgi?id=253091Signed-off-by: default avatarSui Chen <suichen6@gmail.com>
    Tested-by: default avatarDamian Ivanov <damianatorrpm@gmail.com>
    Signed-off-by: default avatarTejun Heo <tj@kernel.org>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    d9f48c46
ahci.c 56.9 KB