• Tejun Heo's avatar
    sata_nv: don't diddle with nIEN on mcp55 · f3faf8fc
    Tejun Heo authored
    On mcp55, nIEN gets stuck once set and liteon blueray rom iHOS104-08
    violates ATA specification and fails to set I on D2H Reg FIS if nIEN
    is set when the command was issued.  When the other party is following
    the spec, both devices can work fine but when the two flaws are put
    together, they can't talk to each other.
    
    mcp55 has its own IRQ masking mechanism and there's no reason to mess
    with nIEN in the first place.  Fix it by dropping nIEN diddling from
    nv_mcp55_freeze/thaw().
    
    This was originally reported by Cengiz.  Although Cengiz hasn't
    verified the fix yet, I could reproduce this problem and verfiy the
    fix.  Even if Cengiz is experiencing different or additional problems,
    this patch is needed.
    Signed-off-by: default avatarTejun Heo <tj@kernel.org>
    Reported-by: default avatarCengiz Günay <cgunay@emory.edu>
    Cc: stable@kernel.org
    Signed-off-by: default avatarJeff Garzik <jgarzik@redhat.com>
    f3faf8fc
sata_nv.c 69.6 KB